Updated migrations.rst to correct usage of CURRENT_TIMESTAMP.
Updated migrations.rst to correct usage of CURRENT_TIMESTAMP.

The documentation "Creating a Table" for was using CURRENT_TIMESTAMP on a datetime field instead of a timestamp field.
dankempster/phinx,robmorgan/phinx,Thamrongsak/phinx,ikagawa/phinx,rquadling/phinx,aCodify/phinx,daniel-gomes-sociomantic/phinx,aCodify/phinx