Fix incorrect path in CONTRIBUTING file
Improve error reporting incase of invalid certificate.
Check around the X509 cert validation only.
Improved Error Message.
Merge branch 'KNIFE-193'
Fixes:
1. Host name is not a compulsory parameter anymore. Use Role name as
default
2. Explicitly mention that SSH User/Password or WinRM creds are missing
3. Remove unecessary statement
3. Role Size defaults to Small
Merge branch 'KNIFE-197'