setup.py: Add monsoon's dependencies to extras_require
diff --git a/setup.py b/setup.py
index 47a4475..e7753d4 100644
--- a/setup.py
+++ b/setup.py
@@ -74,6 +74,7 @@
     extras_require={
         'daq': ['daqpower'],
         'doc': ['sphinx'],
+        'monsoon': ['python-gflags'],
     },
     # https://pypi.python.org/pypi?%3Aaction=list_classifiers
     classifiers=[