Add top-level attributes for git M-P packages

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

@@ -33,7 +33,7 @@ class Mfem(Package):
     tags = ['FEM', 'finite elements', 'high-order', 'AMR', 'HPC']
 
     homepage = 'http://www.mfem.org'
-    url      = 'https://github.com/mfem/mfem'
+    git      = 'https://github.com/mfem/mfem.git'
 
     maintainers = ['goxberry', 'tzanio', 'markcmiller86', 'acfisher',
                    'v-dobrev']
@@ -62,8 +62,7 @@ class Mfem(Package):
 
     # 'develop' is a special version that is always larger (or newer) than any
     # other version.
-    version('develop',
-            git='https://github.com/mfem/mfem', branch='master')
+    version('develop', branch='master')
 
     version('3.4.0',
             '4e73e4fe0482636de3c5dc983cd395839a83cb16f6f509bd88b053e8b3858e05',