Support changing remote branches. (#302)
Support changing remote branches. (#302)

* Support changing remote branches.

* Clarify git rev-parse

* Support other test Coordinator

* Be able to build nextversion

netsec-ethz/scion-coord,netsec-ethz/scion-coord,netsec-ethz/scion-coord,netsec-ethz/scion-coord,netsec-ethz/scion-coord,netsec-ethz/scion-coord