bump version number, update gitignore
rewrite helper to be more clean
update oauth API
update rate limits API
update rate friends API
update users API
update status API
Merge branch 'feature/error_explaination' into develop
filter out nil value in query argument of send_request method
fix issue of sending nil value in send_request argument
Merge branch 'feature/filter_out_nil_params' into develop
Bump version number
Merge branch 'release/0.3.0'