Fix BATS testing on WSL (#104)

ffes · paulirish · commit d97b7f36aadb · 2017-12-01T12:30:50.000-08:00
The $openopt resulted in unexpected results during testing
diff --git a/git-open b/git-open
@@ -171,3 +171,5 @@ fi
 
 # open it in a browser
 ${BROWSER:-$open} $openopt "$openurl"
+
+unset openopt
