Don't use Jedi 0.14 for now because it breaks the server (#607)

Author: ccordoba12

setup.py

@@ -36,7 +36,7 @@
         'future>=0.14.0',
         'futures; python_version<"3.2"',
         'backports.functools_lru_cache; python_version<"3.2"',
-        'jedi>=0.13.2',
+        'jedi>=0.13.2,<0.14',
         'python-jsonrpc-server>=0.1.0',
         'pluggy'
     ],