ECP VELOC Package update (#8910)

* update of veloc & dep versions (replace old non-working versions)

* veloc doesn't work with gcc <= 4.9.3

* explicitly pass MPI to CMake for veloc build

var/spack/repos/builtin/packages/rankstr/package.py

@@ -35,7 +35,7 @@ class Rankstr(CMakePackage):
     tags = ['ecp']
 
     version('master', branch='master')
-    version('0.0.1', 'abe06fa6a78cfe20ec0c78717ac2f2ed')
+    version('0.0.2', sha256='c16d53aa9bb79934cbe2dcd8612e2db7d59de80be500c104e39e8623d4eacd8e')
 
     depends_on('mpi')