test/run: unset GREP_OPTIONS

Fixes #116.

R=r
https://golang.org/cl/152106
diff --git a/test/run b/test/run
index 93382d1..1f921e7 100755
--- a/test/run
+++ b/test/run
@@ -29,6 +29,7 @@
 export L=${A}l
 export GOTRACEBACK=0
 export LANG=C
+unset GREP_OPTIONS	# in case user has a non-standard set
 
 failed=0