Disable the NumericLiterals cop for rubocop

- Disable the NumericLiterals cop in the .rubocop.yml file - this cop enforces
  an underscore '_' every 3 characters of an integer. This doesn't make much
  sense in our use case and reduces readability. Especially for port numbers.
- Remove any existing entries that were abiding by the NumericLiterals
  cop.

Change-Id: I3840241c1f5326e1bee72a9092e97e10efa6682f
Addresses: blueprint rubocop-integer