Accepting request 562827 from home:eeich:branches:fix-compilers-hpc

- Add gcc7 as additional compiler flavor for HPC on SLES.
- Add support for mpich and openmpi3 for HPC.

OBS-URL: https://build.opensuse.org/request/show/562827
OBS-URL: https://build.opensuse.org/package/show/science:HPC/mpiP?expand=0&rev=13

_multibuild

@@ -1,4 +1,6 @@
 <multibuild>
   <package>gnu-openmpi-hpc</package>
+  <package>gnu-openmpi3-hpc</package>
   <package>gnu-mvapich2-hpc</package>
+  <package>gnu-mpich-hpc</package>
 </multibuild>