[WIP] Added List labels and milestones command; Added Label command; Some refactoring
Added conditions based on the options; Added labels validation.
Added cache files per issues/pr and also by organization/repository
Added "current labels" of an issue to the output. Add possibility to add
multiple labels separated by commas.
Fixed typo
create folder rather than firing an exception
create cache folder and also fix bug with title key on milestone command
Merge pull request #12 from danielcsgomes/new-commands

[WIP][New Commands] Label issues, List milestones, List labels
Merge pull request #13 from cordoval/new-commands

New commands fixes
plug some fixes to account for git@github... and http:// differences
Merge pull request #15 from cordoval/fix-some-bugs-with-git-formatted-urls

plug some fixes to account for git@github... and http:// differences