update description

Author: mganahl

setup.py

@@ -19,7 +19,8 @@
 with open('tensornetwork/version.py') as f:
   exec(f.read(), globals())
 
-description = ('A high level tensor network API for tensorflow.')
+description = ('A high level tensor network API for '
+               'accelerated tensor network calculations.')
 
 # Reading long Description from README.md file.
 with open("README.md", "r") as fh: