Ceph » devops

Add to install-deps.sh a test that verifies none of the requirements.txt file are more recent than an existing wheelhouse directory. If that's the case, wipe out the wheelhouse directory and rebuild it.
At present if a new dependency is added to the requirements.txt file and a wheelhouse directory has been populated prior to this addition, it will not be updated and the dependency won't be available when running with --no-index.
This border case won't happen to developers because they never run with --no-index and the missing package will be collected from the network. It does not happen for the make check bot either because it removes the wheelhouse directories between two runs (and populate them with network before using them without network as a side effect of executing ./run-make-check.sh). It does not happen for jenkins either because jenkins never runs without network.
At the moment it's only a theoritical problem but it would be worth fixing before someone gets very confused.