Delete .test_config (dart-lang/pool#47)

diff --git a/pkgs/pool/.test_config b/pkgs/pool/.test_config
deleted file mode 100644
index 412fc5c..0000000
--- a/pkgs/pool/.test_config
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-  "test_package": true
-}
\ No newline at end of file