Set default branch to 0.8.x

Make gitreview's default branch reflect the branch we are on.

Change-Id: Ib5b6417340a0f7eb5b138385dda723a085dee818
Switch over to oslosphinx

oslosphinx is the new name of oslo.sphinx

Change-Id: I70ac51fcd7148832f94b7aae5049893bc650846d
Closes-Bug: #1277168
(cherry picked from commit f487cff4358ebed0d5ec618cb54b5772543e79c9)