SDK should prompt for the database logins again if invalid logins were entered

Merged at https://github.com/openmrs/openmrs-sdk/commit/eabdcbd40b293fa72e0b1845c68929a4efaa8be7. Thanks @herman muhereza!

PR at https://github.com/openmrs/openmrs-sdk/pull/324

Open

The changes in the pull request above make sure that instead of failing immediately when database credentials are not correct, the sdk now:

• Allows up to 3 attempts to enter correct credentials

• Prompts the user for new username/password after each failed attempt

• Shows clear feedback about which attempt they're on (e.g., "attempt 2 of 3")

• Throws a MojoExecutionException only after all 3 attempts fail
  
  cc: @Wikum Weerakutti

@Wikum Weerakutti doesn’t this require more description, for example like after how many attempts should we finally call it and throw the mojoexception?