Set up acra for mUzima 2.0

Install a new instance of acralyzer and create a sub-domain acra.muzima.org, for mUzima 2.0 and later versions, and update muzima-android to use the new link. The reason for this is

1. To move some of the load on test server to other servers
2. To create a sub-domain for acra so that in case the server IP address changes, we don't need to require making changes in code as well.