cassandra_migrate connects to Cassandra every time our rails application starts up

[cosgroveb]

Although we probably want our application to die if it itself cannot connect to Cassandra, we find it a little weird that the migrator gem by virtue of its railtie actually connects to our keyspace during application startup regardless of whether or not we're invoking a cassandra migration rake task.

https://github.com/hsgubert/cassandra_migrations/blob/master/lib/cassandra_migrations/railtie.rb#L5

It seems like it would be more appropriate to move this logic (ultimately Cassandra.start!) into the start of every rake task. Thoughts?

[cosgroveb]

We're going to add require => false for cassandra_migrations in our application Gemfile and require it manually in our custom migration tasks.