add .gitreview

git review uses this file to build the git url.

Change-Id: Ia35aeb33d43ace3c71689d5acbb8d1259ccb7b42
diff --git a/.gitreview b/.gitreview
new file mode 100644
index 0000000..3637d15
--- /dev/null
+++ b/.gitreview
@@ -0,0 +1,3 @@
+[gerrit]
+host=gerrit.osmocom.org
+project=pysim