Rubocop cleanup - removing individual directory .rubocop.yml files

- Remove directory/.rubocop.yml files
- Adjust Strainerfile to use the single .rubocop.yml
- Adjust .rubocop.yml ot reference all directories

Change-Id: I4323a1d1b626001c0b0dc05bec473b16c637f485
Addresses: blueprint rubocop-for-metering