fix docs for progressbar2 (#503)

zsdonghao · luomai · commit b2080df46dd1 · 2018-04-18T10:56:43.000+08:00
Update requirement.txt for readthedocs
diff --git a/docs/requirements.txt b/docs/requirements.txt
@@ -1,5 +1,6 @@
 matplotlib
 pymongo
+progressbar2==3.37.0
 scikit-image
 scipy
 sphinx==1.7.1
