Enable multi accounts
Code style change / method rename pointed out by @vesan ( https://github.com/muojp/omnifocus-pivotaltracker/commit/5edbdce70b3f5357a58049a234df1413c2eecf17#commitcomment-4910375 )
Simplify code (thanks: https://github.com/muojp/omnifocus-pivotaltracker/commit/5edbdce70b3f5357a58049a234df1413c2eecf17#commitcomment-4914428 )
Merge pull request #4 from muojp/enable_multiple_accounts

Enable multi accounts