Bump flask-migrate from 2.2.1 to 2.3.0

Bumps [flask-migrate](https://github.com/miguelgrinberg/flask-migrate) from 2.2.1 to 2.3.0.
- [Release notes](https://github.com/miguelgrinberg/flask-migrate/releases)
- [Changelog](https://github.com/miguelgrinberg/Flask-Migrate/blob/master/CHANGELOG.md)
- [Commits](https://github.com/miguelgrinberg/flask-migrate/compare/v2.2.1...v2.3.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Pipfile.lock

@@ -211,11 +211,11 @@
         },
         "flask-migrate": {
             "hashes": [
-                "sha256:83ebc105f87357ddd3968f83510d2b1092f006660b1c6ba07a4efce036ca567d",
-                "sha256:cd1b4e6cb829eeb41c02ad9202d83bef5f4b7a036dd9fad72ce96ad1e22efb07"
+                "sha256:a25b3d2d2bb0f0724f104afbadae888a4b942e7221b451f720c69698d4863da7",
+                "sha256:cb7d7b37feb68e3a8769aaf7a3954ecbdcd9bdeef8f21cede9eaa07c813f8af9"
             ],
             "index": "pypi",
-            "version": "==2.2.1"
+            "version": "==2.3.0"
         },
         "flask-sqlalchemy": {
             "hashes": [

requirements.txt

@@ -15,7 +15,7 @@ cryptography==2.3.1
 csscompressor==0.9.5
 decorator==4.3.0
 doit==0.31.1
-flask-migrate==2.2.1
+flask-migrate==2.3.0
 flask-sqlalchemy==2.3.2
 flask==1.0.2
 gunicorn==19.9.0