Merge pull request Ladicle#30 from mkgrei/fix-non-namespaced

Fixes requiring namespace when namespace variable is not set

Add validation test

Merge pull request Ladicle#22 from Ladicle/rename-cmd

Rename command from kubectl-bindrole to kubectl-rolesum

Merge pull request Ladicle#21 from Ladicle/msg-and-desc

Provide readable error and help messages

Merge pull request Ladicle#18 from Ladicle/usage

Update help message

Merge pull request Ladicle#8 from Ladicle/support-auth-plugins

Support client auth plugins

Merge pull request Ladicle#5 from ohatakky/fix_auth_gcp

 Import the gcp's auth plugin.

Add installation and usage guide