Add `repoc` to the .gitignore file

This is currently the only generated file not present in the .gitignore

Apparently it comes from the usage of the "imp" module in main.py

Change-Id: I685dc252d0c822818434a8e5f493f77b63a66f03
Signed-off-by: Chirayu Desai <cdesai@cyanogenmod.org>

.gitignore

@@ -1,2 +1,3 @@
 *.pyc
 .repopickle_*
+/repoc