Update to ansible 2.7 for linting
We run ansible 2.7 with zuul, so update the version we use for linting.
@@ -32,7 +32,7 @@ deps =
# Unfortunately pip doesn't do actual dependency resolution, so
# we need to manually ansible at the top level to the same as
# zuul requirements.txt
- ansible>=2.5.1,<2.6
+ ansible>=2.7.0,<2.8
ansible-lint<4
hacking>=1.1,<1.2
bashate>=0.2
