requirements: avoid hard/versionized dependencies
requirements: avoid hard/versionized dependencies

There is no strong reason to pine to a given version of our
dependencies. Thurs the situation may probably evolve in the future.

Change-Id: I3a0bccca41332b09d4cd01280c0aaa8ead8bca4e

goneri/dci-control-server,enovance/dci-control-server,goneri/dci-control-server,enovance/dci-control-server,redhat-cip/dci-control-server,goneri/dci-control-server,redhat-cip/dci-control-server,goneri/dci-control-server