Add Gerrit path to README.rst
Add Gerrit path to README.rst

Change-Id: I8006be6c484dc1d7a253e4250d9ab1e7d3acae41

DougFirErickson/ceres-solver,whuaegeanse/ceres-solver,ysonggit/ceres-solver,DougFirErickson/ceres-solver,ysonggit/ceres-solver,ysonggit/ceres-solver,ysonggit/ceres-solver,whuaegeanse/ceres-solver,whuaegeanse/ceres-solver,DougFirErickson/ceres-solver,whuaegeanse/ceres-solver,DougFirErickson/ceres-solver