Enable hacking checks

[Cindy Pallares]

There are certain hacking rules that have been disabled for one reason or another. We should enable them.

H233 Python 3.x incompatible use of print operator
H303 no wildcard import
H404 multi line docstring should start with a summary
E265 block comment should start with '# '
H405 multi line docstring summary not separated with an empty line
E123 closing bracket does not match indentation of opening bracket's line
H238 old style class declaration, use new style (inherit from `object`)
E128 continuation line under-indented for visual indent

[Cyril Roelandt (cyril-roelandt)]

The only checks glanceclient currently ignores are https://www.flake8rules.com/rules/W504.html and https://www.flake8rules.com/rules/E731.html.

Commit cd5925bc60a5298ecc7182bf058a1b3a5bec30cf enabled:
 H233 Python 3.x incompatible use of print operator
 H303 no wildcard import
 H404 multi line docstring should start with a summary

Commit ec0f2dfd8500d230895e286462aaf69c43777038 enabled:
 E265 block comment should start with '# '
 H405 multi line docstring summary not separated with an empty line
 E123 closing bracket does not match indentation of opening bracket's line
 H238 old style class declaration, use new style (inherit from `object`)
 E128 continuation line under-indented for visual indent

I'll consider this bug fixed. Feel free to reopen if E731 and W504 are more important than I realize.