* New module postgresql_ping: simple module to check remote PostgreSQL server availability.
* New module postgresql_ping: simple module to check remote PostgreSQL server availability, doc fixes
* postgresql_ping: added integration tests
* New module postgresql_ping: misc changes
* New module postgresql_ping: change return suit
* New module postgresql_ping: tests reformatting, return value
* Various cosmetic/documentation fixes
* A few more fixes
* And even more cleanups
* Fix PEP8 issue
