[arc] Remove unittesting from arcconfig

Summary:
Unittests aren't working, and I don't think they ever were. Just remove
them, so that we don't have  to write `arc --nounit` all the time.

Reviewers: grosser, Meinersbur, bollu

Subscribers: bollu, pollydev, llvm-commits

Differential Revision: https://reviews.llvm.org/D46869

llvm-svn: 332355

Author: pfaffe

polly/.arcconfig

@@ -1,9 +1,4 @@
 {
   "repository.callsign" : "PLO",
-  "conduit_uri" : "https://reviews.llvm.org/",
-  "history.immutable" : true,
-  "load" : [
-    "utils/arcanist/LitTestEngine"
-  ],
-  "unit.engine" : "LitTestEngine"
+  "conduit_uri" : "https://reviews.llvm.org/"
 }