Drop shard key updates.

Currently, as outlined in issue #6, shard keys can't be updated in
mongodb instances.  To workaround this issue (not solve) we're silently
ignoring the username change requests.

This needs to be verified and ensure that users can still be created.
added pip requirements.txt. separated unit test and base requirements
Merge pull request #13 from keeb/pip

Add requirements.txt
Rename consumers → spread.
Add development section to the README.
Move wsgi files to libexec.
Merge branch 'master' into issues/7
Remove incorrect username parameter from redis.

The redis database doesn't use a username for a connection.  It only
uses a password for authorization.

This should solve issue #7 but this still needs to be reviewed and
tested before merged into master.