Bump flask from 0.12.2 to 1.0

Bumps [flask](https://github.com/pallets/flask) from 0.12.2 to 1.0.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/master/CHANGES.rst)
- [Commits](pallets/flask@0.12.2...1.0)

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

Author: dependabot[bot]

requirements.txt

@@ -7,7 +7,7 @@ cfgv==1.0.0
 chardet==3.0.4
 click==6.7
 coverage==4.5.1
-Flask==0.12.2
+Flask==1.0
 flask-lambda-python36==0.1.0
 http-prompt==0.11.2
 httpie==0.9.9