Paginate github sync results. Fixes #915

Repo sync wasn't working past 100 items because pagination wasn't
implemented.
Fix exception message typo
Merge pull request #928 from malept/fix-exception-message-typo

Fix exception message typo
adding Vietnamese to languages
Merge pull request #933 from psychobunny/patch-1

Adding Vietnamese to languages
Merge pull request #921 from zimbatm/github-pagination

Paginate github sync results. Fixes #915