Merge pull request #4 from holmboe/develop

Add pylint checker for file encoding
`salttesting.pylintplugins` is a package.
Actually check for IPV6 support. Fixes #5.
`v0.5.1` was released, `0.5.2` is the current develop version.
Added `requires_salt_modules` which skips tests if such modules were not loaded on the minion.
Log start and stop execution.
Provide a PEP8 to PyLint bridge to use the power of PyLint in PEP8.
Only append PEP8 messages which generate a code. Skip messages handled by PyLint.
Provide a message description equal to it's message to avoid PyLint's deprecation.
Add test for no-encoding-in-empty-file (W9905)

See
https://github.com/saltstack/salt-testing/pull/4#issuecomment-24727655
for discussion.