Bump pytest-cov from 2.6.1 to 2.7.1

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 2.6.1 to 2.7.1.
- [Release notes](https://github.com/pytest-dev/pytest-cov/releases)
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pytest-dev/pytest-cov/compare/v2.6.1...v2.7.1)

Pipfile.lock

@@ -570,11 +570,11 @@
         },
         "pytest-cov": {
             "hashes": [
-                "sha256:0ab664b25c6aa9716cbf203b17ddb301932383046082c081b9848a0edf5add33",
-                "sha256:230ef817450ab0699c6cc3c9c8f7a829c34674456f2ed8df1fe1d39780f7c87f"
+                "sha256:2b097cde81a302e1047331b48cadacf23577e431b61e9c6f49a1170bbe3d3da6",
+                "sha256:e00ea4fdde970725482f1f35630d12f074e121a23801aabf2ae154ec6bdd343a"
             ],
             "index": "pypi",
-            "version": "==2.6.1"
+            "version": "==2.7.1"
         },
         "pytest-redis": {
             "hashes": [

requirements-dev.txt

@@ -15,7 +15,7 @@ port-for==0.4
 psutil==5.6.2
 py==1.8.0
 pyparsing==2.4.0
-pytest-cov==2.6.1
+pytest-cov==2.7.1
 pytest-redis==1.3.2
 pytest==4.6.1
 redis==3.2.1