Sync up Flask version with global-requirements
As Flask version was updated we need to update our own requirements.txt
to avoid reqirements-check job to fail on every patch that changes
anything related to requirements.
Hopefully that's the last issue introduced by Flask upgrade.
# process, which may cause wedges in the gate later.
cotyledon>=1.3.0 # Apache-2.0
-Flask!=0.11,<1.0,>=0.10 # BSD
+Flask!=0.11,>=0.10 # BSD
kuryr-lib>=0.5.0 # Apache-2.0
pbr!=2.1.0,>=2.0.0 # Apache-2.0
requests>=2.14.2 # Apache-2.0
