Out-of-source test-only runs are bound to fail

This is not an issue per see, but more like a feature request. With the current test strategy implemented in bob.admin#100 (closed), conda packages are supposed to contain all material that is required to test them.

This is not true for the doc directory of source packages, therefore testing any package inside bob out of its source present is bound to fail.

My impression is that this could be mitigated if we were not "building" the documentation during "test" time, but rather during build time.

It would be nice to understand why that is not the case, @amohammadi.