Some environments might disable access to `/dev/tty`, fall
back to '80' in such scenarios.
Move to 'cheggaaa/pb' package for better cross platform
support on fetching terminal width.
Fixes#1891
- Upon first time invocation ``minio controller`` would create access keys and secret id
- Upon request passing 'keys' arg ``minio controller`` would provide the keys
- Add colorized notification
Harshavardhana