Postgres scaler

[dimberman]

No description provided.

[msftclas]

All CLA requirements met.

[ahmelsayed]

Thanks @dimberman. The change looks good to me. I have a couple of minor comments from just looking at the code.

[dimberman]

Thank you @ahmelsayed I have addressed your comments

[tomkerkhove]

@ahmelsayed Late to the game but something I'd keep an eye open for the future is:

1. Consistency - Here it's called connStr, others use connection and probably have more ways of configuring same thing with different name
2. Scaler is called postgres rather than postgreSQL, is that how it's typically called?

Not criticizing, just taking mental note for the future ones as we might want to align them a bit more but should've reviewed as well - Sorry!