Fix bug in tools.py with module_name not defined

Author: rpep

setup.py

@@ -180,9 +180,7 @@
 ]
 
 for folder in glob.glob(os.path.join(USER_DIR, '*/')):
-    module_name = folder.split('/')[-2]
-    user_sources = get_user_module_sources(folder)
-
+    module_name, user_sources = get_user_module_sources(folder)
     ext_modules.append(
        Extension("fidimag.extensions.user.{}".format(module_name),
           sources=user_sources,

tools.py

@@ -16,6 +16,7 @@ class BuildError(Exception):
 
 
 def get_user_module_sources(folder):
+    module_name = folder.split('/')[-2]
     print('Found User Module: {}'.format(folder))
     user_sources = glob.glob(folder + '/*.pyx')
     print('\tFound Cython sources: {}'.format(user_sources))
@@ -31,4 +32,4 @@ def get_user_module_sources(folder):
     print(cfilename)
     user_sources += glob_files(folder, excludes=[cfilename])
 
-    return user_sources
+    return module_name, user_sources