Fix lint and charm proof errors

[ktsakalozos]

Should also fix some of the Kubernetes bundle failures on CWR

Fixes:
charm proof

W: summary should be less than 72
E: Charm must have either a maintainer or maintainers field
W: Metadata missing required field "tags"
I: No icon.svg file.

and make lint

py34 create: /home/jackal/workspace/charms/trusty/nginx/.tox/py34
ERROR: InterpreterNotFound: python3.4
py35 installed: flake8==3.2.0,mccabe==0.5.2,pkg-resources==0.0.0,py==1.4.31,pycodestyle==2.2.0,pyflakes==1.3.0,pytest==3.0.4
__________________________________________________________________________________ summary __________________________________________________________________________________
SKIPPED:  py34: InterpreterNotFound: python3.4
  py35: skipped tests
  congratulations :)
reactive/nginx.py:24:1: E305 expected 2 blank lines after class or function definition, found 1
Makefile:17: recipe for target 'lint' failed
make: *** [lint] Error 1

[marcoceppi]

Some feedback, LGTM otherwise.

[marcoceppi]

This is a layer and not a charm. Maintainers field should not be populated here. Otherwise it shows up for top layers including this.

charm proof is run against a compiled charm and not against a single layer

[ktsakalozos]

Fair enough, I dropped the maintainers and tags in the last commit.