WIP: Adding SQL server and Postgres
Added SQL and PostgreSQL support, and dbproducts.json
Fixed duplicated engines bug
RDS: Added actual currency
FB 4877: First param in getLoadBalancerHealthCheck was incorrectly annotated as @Nullable
FB 4877: Second parameter is nullable and has to be checked before accessed to avoid NPE
Merge pull request #167 from maksimov/develop

Added SQL and PostgreSQL support, and dbproducts.json