Fixed oslotest version pin

It turned out that pip is too smart and knows that 1.1.0.0a1 is less
than 1.1.0. We have 1.1.0.0a1 on PyPI for now, so we need to require
that specific version until the final release is available.

Change-Id: I23d85cf1237177561955df05c752871c443e3630
Merge "Fixed oslotest version pin"