Include tests when packaging (#635)

Fixes #620
diff --git a/Cargo.toml b/Cargo.toml
index 2c1be1a..3415f11 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,7 +15,6 @@
   ".gitignore",
   ".travis.yml",
   "deploy.sh",
-  "test/**/*",
 ]
 
 [features]