Remove most PG specific type subclasses

The latest version of the PG gem can actually convert the primitives for
us in C code, which gives a pretty substantial speed up. A few cases
were only there to add the `infinity` method, which I just put on the
range type (which is the only place it was used). Floats also needed to
parse `Infinity` and `NaN`, but it felt reasonable enough to put that on
the generic form.

1 files changed, 1 insertions, 1 deletions

diff --git a/Gemfile b/Gemfile
index 4299ab337d..08aa842d2f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -85,7 +85,7 @@ platforms :ruby do
   gem 'sqlite3', '~> 1.3.6'
 
   group :db do
-    gem 'pg', '>= 0.15.0'
+    gem 'pg', '>= 0.18.0'
     gem 'mysql', '>= 2.9.0'
     gem 'mysql2', '>= 0.3.13'
   end