Ignore some folders.

kennytm · kennytm · commit 57356b36fc42 · 2017-06-02T01:14:25.000+08:00
- /src/target -- created when trying to directly `cargo build` on a single
  package.
diff --git a/.gitignore b/.gitignore
@@ -101,3 +101,4 @@ version.ml
 version.texi
 .cargo
 !src/vendor/**
+/src/target/
