Some documentation, drops 1.8.7 from travis

.travis.yml

@@ -1,8 +1,6 @@
 rvm:
-  - 1.8.7
   - 1.9.3
   - 2.0.0
-  - jruby-18mode
   - jruby-19mode
 
 before_script:

README.md

@@ -13,6 +13,10 @@ the gem please ask the question on
 [Stack Overflow](http://stackoverflow.com). Be sure to tag the
 question with `DockYard` so we can find it.
 
+## Note ##
+PostgresExt is dropping support for Ruby 1.8.7 with the next minor
+release.
+
 ## Installation
 
 Add this line to your application's Gemfile:

docs/type_casting.md

@@ -49,3 +49,22 @@ person_2.favorite_numbers
 person_2.favorite_numbers.first.class
 # => Fixnum
 ```
+
+## Ranges
+Like array objects, postgres\_ext supports range types as well.
+Numrange, in4range, int8range, daterange, tsrange, and tstzrange are all
+supported, but there are some notable caveats.
+
+### Int and Date ranges
+As integers and days are discrete measurements, PostgreSQL will
+normalize these ranges as they are store in the database. PostgreSQL
+will convert end-inclusive ranges to end-exclusive, meaning that `0..4`
+becomes `0...5`. Developers should be aware of this when using integer
+and date ranges, since ruby will treat these ranges differently from
+PostgreSQL. 
+
+### Timestamp with and without timezone
+Ruby/Rails 3.2.x does not support datetime ranges that begin or end with
+infinity. Rails 4 has patched datetime and time so that infinity
+terminated ranges work, but currently postgres\_ext has not patched the
+required methods.