support for upper-roman, upper-alpha, lower-roman and lower-alpha for list-style-type on ul and ol tags
updated httplib2 to version 0.7.6, 0.6.0 looks to be no longer in pypi.  including in this PR from another PR.
added in a few tests for the roman numeral conversion
Merge pull request #65 from andrewschoen/roman-numerals

Additional support for list-style-type options