Major refactor; Three new git commands; Bump to 0.2.0

add github_api gem

refactor git remote data extraction

add AUTHOR, REPO and URL constants to Ghit

remove constants; add repo_stats

add rainbow gem; formatting to repo_stats

git-stats draft version

draft contributors

git frequency

extract repo stats to new namespace; add punch card

refactor stats/contribitors

refactor stats/code_frequency

add new commands to README

improve readme

BUMP!