Added json support for tokens

[shicholas]

In the installation generator script, the migration template checks to see if the app is using postgres by seeing what sub-class of ActiveRecord::ConnectionAdapter the app is using. If it is postgres, the app will use a token column instead of a text one.

[shicholas]

Since the tests run with SQLite, what do you think the best way to add tests are? I just did it manually.

[shicholas]

hmm sorry it looks like my branch is out of sync. I'll update that soon

edit: updated

[nicolas-besnard]

Could be nice to change column too ;)

[shicholas]

fwiw, I got the inspiration from this comment: #121 (comment)

[booleanbetrayal]

@shicholas - I think we need an additional check on pg_types as json was not supported until 9.3, and just checking the adapter is insufficient. see also: http://www.postgresql.org/docs/current/interactive/catalog-pg-type.html

Likewise, MySQL is now rolling json support, so we should account for that possibility as well. Not sure about SQLite at this point ...

[shicholas]

okay sounds good, I will do a check for mysql and postgres with the right versions. I'll push up the some code soon. How should I test this though? Should we run the tests w/ those database versions?

[shicholas]

pushed, let me know what you think.

[booleanbetrayal]

@shicholas - LGTM ... would you mind rebasing and squashing your commits?

[shicholas]

np, rebased and squashed.

[booleanbetrayal]

thanks @shicholas !