fix setup script

CHANGES.md

 
 ## Breaking API changes.
 
-tensorpack is still in early development, and API changes can happen.
-The backward compatibilty will be __preserved for several months__, with a deprecation warning,
-so you won't need to look at here very often.
+Tensorpack is in development, and API changes can happen.
+The backward compatibilty will be __preserved for at least several months__, with a deprecation warning,
+so you don't need to look at here very often.
 
 Here are a list of things that were changed, starting from an early version.
-TensorFlow itself also changed APIs before 1.0 and those are not listed here.
+TensorFlow itself also APIs changes and those are not listed here.
 
 + [2018/04/05] msgpack is replaced by pyarrow. If you want compatibility with old serialized data,
 	`export TENSORPACK_SERIALIZE=msgpack`.

MANIFEST.in

-include requirements.txt

setup.py

@@ -13,8 +13,8 @@ libinfo_py = path.join(this_directory, 'tensorpack', 'libinfo.py')
 last_line = open(libinfo_py, "rb").readlines()[-1].strip()
 exec(last_line)
 
-with open(path.join(this_directory, 'README.md'), encoding='utf-8') as f:
-    long_description = f.read()
+with open(path.join(this_directory, 'README.md'), 'rb') as f:
+    long_description = f.read().decode('utf-8')
 
 setup(
     name='tensorpack',