Update webassets to v0.11.1
diff --git a/requirements.txt b/requirements.txt
index eb5b0b9..5ebfd53 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,9 +1,7 @@
-webassets==0.11
+webassets==0.11.1
 
 cssmin==0.2.0
 pyScss==1.3.4
 slimit==0.8.1
 
-# Ply 3.6 has an issue that causes slimit to fail
-# https://github.com/dabeaz/ply/issues/63
 ply==3.8