Fix help message of update_issues
Merge pull request #1 from danjo-m/fix_help_message

Fix help message of update_issues
Implement get_team_members command
Merge pull request #4 from okada-takuya/okada/team_members

Implement get_team_members command
Implement add_collaborator command
Merge pull request #2 from okada-takuya/okada/add_collaborators

Implement add_collaborator command
Do not require title and body when updating an issue
Merge pull request #3 from okada-takuya/okada/do_not_erase_body_of_issue

Do not require title and body when updating an issue
Separate formatter classes into individual files
Enumerate all formatter names in help message
Adjust Namespace
Fix typo
Fix some errors in help messages
Separate command classes into individual files
Add show command
Changes for review
Add create_iteration command
Fix typo
Change show format
Add comments command