Log Message:
Update ruby-pg to 0.18.2.

== v0.18.2 [2015-05-14] Michael Granger <ged@FaerieMUD.org>

Enhancements:

- Allow URI connection string (thanks to Chris Bandy)

Bugfixes:

- Speedups and fixes for PG::TextDecoder::Identifier and quoting behavior
- Revert addition of PG::Connection#hostaddr [#202].
- Fix decoding of fractional timezones and timestamps [#203]
- Fixes for non-C99 compilers
- Avoid possible symbol name clash when linking againt static libpq.