Add a few directories to .gitignore.

Change-Id: Ifd81c623c69629d58e7dca6aa63c3d7117f5999e
(cherry picked from commit 235d94c4edf039c6ef84f140a4c70ddd1639ba63)
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1346
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: Nong Li <nong@cloudera.com>
(cherry picked from commit 84f6f4af4372b71a055451d02a84f06b2e1f74fd)
(cherry picked from commit a1762cc5d0d82436a758d63d945348a85ca23f01)
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1345