Update dependency Flask to v0.12.5

Author: renovate-bot

requirements.txt

@@ -2,7 +2,7 @@ alembic==0.9.2
 certifi==2017.7.27.1
 chardet==3.0.4
 click==6.7
-Flask==0.12.1
+Flask==0.12.5
 Flask-Migrate==2.0.4
 Flask-Script==2.0.6
 Flask-SQLAlchemy==2.2