Add default task to run specs
Fix serialization when store_key option used
Handle nil value
Only mark an attribute as dirty if it actually changes

Every time an attribute was being set, it was being marked as dirty,
regardless of whether it was actually changed or not.

This meant, for instance, if you had an edit form, and a user was to
submit that form without changing anything, the attribute would be
marked as dirty.

This brings it in line with ActiveRecord dirty handling, by only marking
an attribute as dirty if it actually changes.
Ensured contains queries on array fields can handle more than 2 strings (fixed as outlined in #36)
Merge pull request #33 from pwim/rspec-task-for-rake

Add default task to run specs
Merge pull request #34 from pwim/fix-store-key-serialization

Fix serialization when store_key option used
Merge pull request #35 from pwim/improved-dirty-tracking

Improved dirty tracking
Merge pull request #39 from crismali/fix_contains_query_bug

Ensured contains queries on array fields can handle more than 2 strings
bumping rubygems version for some bug fixes
rubocop added
rubocoped the docs
rubocoped the docs -- redux
tweaked readme