Tweak design
Add select sync github or not feature
Get rid of comment :put_litter_in_its_place:
Fix bug in create a new comment

The bug happen when create a new comment on github project.

If project is not github, issue also is not github, so determine if issue is github or not.
Fix checking github
Change argument from number to issue

Because github issue api response has `html_url`, so we don't need create
html_url
Add test in order to increase coverage
Merge pull request #87 from kmiyake/iss-71

チケットをtimecardのみに登録するか、githubへ登録するか選択できる