Fix #6: Only import unittest during test run.

Check command regardless of the USER_WHITELIST

Make sure each file has a trailing newline.

Have chkcrontab be tested first at home.

Not sure why, but this was completely broken. Not sure what I'd been
thinking.

Raise exception if unittest2 not installed for Python < 2.7.
Doing this instead of adding requirement as many (most) installs
won't need to run the tests.

Adds the ability to specify additional whitelist users from the command line

Replaces the manual parsing of whitelisted users from the command line with the OptionParser library.

Adds an a doc comment for the whitelisted users arg.

Point at project page on pypi. Change http links to https.

Bump version for 3.3 support and in order to make a signed tag/release.

Limit the travis status icon to just the master branch.

Apparently github and bitbucket lack some of the more obscure RsT
rendering options.