Merge pull request #1284 from eschnett/eschnett/py-h5py.2

Declare dependency of "py-h5py +mpi" on "py-mpi4py"

var/spack/repos/builtin/packages/py-h5py/package.py

@@ -46,6 +46,7 @@ class PyH5py(Package):
     depends_on('hdf5@1.8.4:')
     depends_on('hdf5+mpi', when='+mpi')
     depends_on('mpi', when='+mpi')
+    depends_on('py-mpi4py', when='+mpi')
 
     # Build and runtime dependencies
     depends_on('py-numpy@1.6.1:', type=nolink)