diff --git a/Pipfile.lock b/Pipfile.lock
index ab51ece..1b92a74 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -88,10 +88,10 @@
         },
         "certifi": {
             "hashes": [
-                "sha256:4c1d68a1408dd090d2f3a869aa94c3947cc1d967821d1ed303208c9f41f0f2f4",
-                "sha256:b6e8b28b2b7e771a41ecdd12d4d43262ecab52adebbafa42c77d6b57fb6ad3a4"
+                "sha256:376690d6f16d32f9d1fe8932551d80b23e9d393a8578c5633a2ed39a64861638",
+                "sha256:456048c7e371c089d0a77a5212fb37a2c2dce1e24146e3b7e0261736aaeaa22a"
             ],
-            "version": "==2018.8.13"
+            "version": "==2018.8.24"
         },
         "cffi": {
             "hashes": [
@@ -146,10 +146,10 @@
         },
         "cloudpickle": {
             "hashes": [
-                "sha256:54858c7b7dc763ed894ff91059c1d0b017d593fe23850d3d8d75f47d98398197",
-                "sha256:ac7acd0dcb1c52fa14873f801efe0c53e6457bcc5f01542cb445a6515d9a4b72"
+                "sha256:6ea4b548f61a4f616b065182716318c7dced8c053517f35ac59cec22802daf3d",
+                "sha256:ce26435f16a855dfbebb1f7f8d967884080b167ee6374d7ff0951aaf2455972b"
             ],
-            "version": "==0.5.3"
+            "version": "==0.5.5"
         },
         "cryptography": {
             "hashes": [
@@ -446,7 +446,7 @@
                 "sha256:a68ac5e15e76e7e5dd2b8f94007233e01effe3e50e8daddf69acfd81cb686baf",
                 "sha256:b5725a0bd4ba422ab0e66e89e030c806576753ea3ee08554382c14e685d117b5"
             ],
-            "markers": "python_version < '4' and python_version != '3.2.*' and python_version >= '2.6' and python_version != '3.0.*' and python_version != '3.1.*' and python_version != '3.3.*'",
+            "markers": "python_version < '4' and python_version != '3.0.*' and python_version >= '2.6' and python_version != '3.3.*' and python_version != '3.2.*' and python_version != '3.1.*'",
             "version": "==1.23"
         },
         "vine": {
@@ -467,10 +467,11 @@
     "develop": {
         "atomicwrites": {
             "hashes": [
-                "sha256:240831ea22da9ab882b551b31d4225591e5e447a68c5e188db5b89ca1d487585",
-                "sha256:a24da68318b08ac9c9c45029f4a10371ab5b20e4226738e150e6e7c571630ae6"
+                "sha256:6b5282987b21cd79151f51caccead7a09d0a32e89c568bd9e3c4aaa7bbdf3f3a",
+                "sha256:e16334d50fe0f90919ef7339c24b9b62e6abaa78cd2d226f3d94eb067eb89043"
             ],
-            "version": "==1.1.5"
+            "markers": "python_version != '3.0.*' and python_version != '3.3.*' and python_version != '3.2.*' and python_version != '3.1.*' and python_version >= '2.7'",
+            "version": "==1.2.0"
         },
         "attrs": {
             "hashes": [
@@ -481,10 +482,10 @@
         },
         "certifi": {
             "hashes": [
-                "sha256:4c1d68a1408dd090d2f3a869aa94c3947cc1d967821d1ed303208c9f41f0f2f4",
-                "sha256:b6e8b28b2b7e771a41ecdd12d4d43262ecab52adebbafa42c77d6b57fb6ad3a4"
+                "sha256:376690d6f16d32f9d1fe8932551d80b23e9d393a8578c5633a2ed39a64861638",
+                "sha256:456048c7e371c089d0a77a5212fb37a2c2dce1e24146e3b7e0261736aaeaa22a"
             ],
-            "version": "==2018.8.13"
+            "version": "==2018.8.24"
         },
         "chardet": {
             "hashes": [
@@ -550,7 +551,7 @@
                 "sha256:27390c35495b0b3eab4720f3e186fac57c520104b84d7016cdc5f70a409f3f0c",
                 "sha256:4d246c7621b877e284c5b0a2cdf0b62406560ff548453ea759aedd11dfca4004"
             ],
-            "markers": "python_version != '3.2.*' and python_version >= '2.6' and python_version != '3.0.*' and python_version != '3.1.*' and python_version != '3.3.*'",
+            "markers": "python_version != '3.0.*' and python_version >= '2.6' and python_version != '3.3.*' and python_version != '3.2.*' and python_version != '3.1.*'",
             "version": "==1.0.0"
         },
         "more-itertools": {
@@ -566,7 +567,7 @@
                 "sha256:6e3836e39f4d36ae72840833db137f7b7d35105079aee6ec4a62d9f80d594dd1",
                 "sha256:95eb8364a4708392bae89035f45341871286a333f749c3141c20573d2b3876e1"
             ],
-            "markers": "python_version != '3.2.*' and python_version != '3.0.*' and python_version >= '2.7' and python_version != '3.1.*' and python_version != '3.3.*'",
+            "markers": "python_version != '3.0.*' and python_version != '3.3.*' and python_version != '3.2.*' and python_version != '3.1.*' and python_version >= '2.7'",
             "version": "==0.7.1"
         },
         "port-for": {
@@ -588,24 +589,24 @@
                 "sha256:cea2557ee6a9faa2c100947637ded68414e12b851633c4ce26e0311b2a2ed539",
                 "sha256:d081707ef0081920533db30200a2d30d5c0ea9cf6afa7cf8881ae4516cc69c48"
             ],
-            "markers": "python_version != '3.2.*' and python_version >= '2.6' and python_version != '3.0.*' and python_version != '3.1.*' and python_version != '3.3.*'",
+            "markers": "python_version != '3.0.*' and python_version >= '2.6' and python_version != '3.3.*' and python_version != '3.2.*' and python_version != '3.1.*'",
             "version": "==5.4.7"
         },
         "py": {
             "hashes": [
-                "sha256:3fd59af7435864e1a243790d322d763925431213b6b8529c6ca71081ace3bbf7",
-                "sha256:e31fb2767eb657cbde86c454f02e99cb846d3cd9d61b318525140214fdc0e98e"
+                "sha256:06a30435d058473046be836d3fc4f27167fd84c45b99704f2fb5509ef61f9af1",
+                "sha256:50402e9d1c9005d759426988a492e0edaadb7f4e68bcddfea586bc7432d009c6"
             ],
-            "markers": "python_version != '3.2.*' and python_version != '3.0.*' and python_version >= '2.7' and python_version != '3.1.*' and python_version != '3.3.*'",
-            "version": "==1.5.4"
+            "markers": "python_version != '3.0.*' and python_version != '3.3.*' and python_version != '3.2.*' and python_version != '3.1.*' and python_version >= '2.7'",
+            "version": "==1.6.0"
         },
         "pytest": {
             "hashes": [
-                "sha256:3459a123ad5532852d36f6f4501dfe1acf4af1dd9541834a164666aa40395b02",
-                "sha256:96bfd45dbe863b447a3054145cd78a9d7f31475d2bce6111b133c0cc4f305118"
+                "sha256:2e7c330338b2732ddb992217962e3454aa7290434e75329b1a6739cea41bea6b",
+                "sha256:4abcd98faeea3eb95bd05aa6a7b121d5f89d72e4d36ddb0dcbbfd1ec9f3651d1"
             ],
             "index": "pypi",
-            "version": "==3.7.2"
+            "version": "==3.7.3"
         },
         "pytest-cov": {
             "hashes": [
@@ -651,7 +652,7 @@
                 "sha256:a68ac5e15e76e7e5dd2b8f94007233e01effe3e50e8daddf69acfd81cb686baf",
                 "sha256:b5725a0bd4ba422ab0e66e89e030c806576753ea3ee08554382c14e685d117b5"
             ],
-            "markers": "python_version < '4' and python_version != '3.2.*' and python_version >= '2.6' and python_version != '3.0.*' and python_version != '3.1.*' and python_version != '3.3.*'",
+            "markers": "python_version < '4' and python_version != '3.0.*' and python_version >= '2.6' and python_version != '3.3.*' and python_version != '3.2.*' and python_version != '3.1.*'",
             "version": "==1.23"
         },
         "versioneer": {