tpope/vim-rails — pull request #301 by a2ikm (2014-01-30 07:10:52+00:00)
Title: Support change_column_null

Add syntax highlighting on `change_column_null` method in migration
files. You can get further detail on it from the API reference:

http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-change_column_null