move tasks to db:mongo namespace so it won't affect AR db tasks
temporary workaround for github.com/adacosta/mongoid_rails_migrations/issues/24
Fix typo in f97c21d
Merge branch 'namespace_mongoid_migrations'
Ignore bin directory
Add pry as development dependency
Add configurable Mongoid::Migrator.migrations_path

With this update it's easier to configure the 
place of the migration files, so you can use AR and
Mongoid migrations too.
Adapt new interface in database.rake