pkg/unittest: added LICENSE
pkg/unittest: added LICENSE

R=rnystrom@google.com

Review URL: https://codereview.chromium.org//135343002

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@31750 260f80e4-7a28-3924-810f-c04153c831b5

ErikGrimes/oauth2,thosakwe/oauth2,dart-lang/oauth2