Update projects list for oslo.test renaming

* projects.txt: Rename openstack/oslo.test to openstack/oslotest.

Change-Id: I2891bc66a659bb773ca6901295462c28118414ea
(cherry picked from commit 9418f80740428c93413dc0dffaa5a8dac67c2739)
Merge "Update projects list for oslo.test renaming" into stable/icehouse