Appveyor rc ci (#187)
Appveyor rc ci (#187)

* use secure opti-test SCIP-6.0 rc for Appveyor CI

* use different env var names

* more fun with Appveyor

* use differnent password assignment

* use differnent password assignment again

* use yet another password assignment

* use yet another password assignment

* test env vars

* test env vars

* test env vars

* test env vars

* test env vars

* test env vars

* test env vars

* test env vars

* test env vars

* clean-up

* run appveyor on all branches

* specify powershell

* specify outfile name

mattmilten/PySCIPOpt,mattmilten/PySCIPOpt,SCIP-Interfaces/PySCIPOpt,SCIP-Interfaces/PySCIPOpt