Revert version of Jedi to 0.12.0 (microsoft#3571)

DonJayamanne · web-flow · commit f5e637536475 · 2018-12-06T10:36:07.000-08:00
* Revert version of Jedi to 0.12.0
* Revert change related to Jedi 0.13.0
* Revert parso as well
diff --git a/news/2 Fixes/3514.md b/news/2 Fixes/3514.md
@@ -0,0 +1 @@
+Revert version of Jedi to 0.12.0.
diff --git a/pythonFiles/completion.py b/pythonFiles/completion.py
@@ -34,7 +34,7 @@ class JediCompletion(object):
 
     def __init__(self):
         self.default_sys_path = sys.path
-        self.environment = jedi.api.environment.Environment(sys.executable)
+        self.environment = jedi.api.environment.Environment(sys.prefix, sys.executable)
         self._input = io.open(sys.stdin.fileno(), encoding='utf-8')
         if (os.path.sep == '/') and (platform.uname()[2].find('Microsoft') > -1):
             # WSL; does not support UNC paths
diff --git a/requirements.txt b/requirements.txt
@@ -1,4 +1,4 @@
-jedi==0.13.1
-parso==0.3.1
+jedi==0.12.0
+parso==0.2.1
 isort==4.3.4
 ptvsd==4.2.0
