Update required version of html5lib to 1.0b10 (#589)

Fixes #588.

Author: chihuahua

tensorboard/pip_package/setup.py

@@ -31,7 +31,7 @@
     'six >= 1.10.0',
     'protobuf >= 3.2.0',
     'werkzeug >= 0.11.10',
-    'html5lib == 0.9999999',  # identical to 1.0b8
+    'html5lib == 0.999999999',  # identical to 1.0b10
     'markdown >= 2.6.8',
     'bleach == 1.5.0',
 ]