Add fixers to some rules

[bary12]

This pull request introduces two major changes:

• Fixers. The following rules are now fixable with --fix. This is Issue Add fixers to a few rules #53
  • check-types
  • newline-after-description
  • require-description-complete-sentence
  • require-hyphen-before-param-description
• require-description-complete-sentence now checks that after a period there's an upper case letter. Before, it only checked the beginning of paragraphs.

All this new behavior is tested.

[gajus]

Is this ready to be reviewed/ merged?

[bary12]

Yes, I made a little mess with the commits but I think it's ready.

[gajus]

Thank you