auto merge of #910 : stepancheg/cargo/travis-install, r=alexcrichton
authorbors <bors@rust-lang.org>
Wed, 19 Nov 2014 19:44:20 +0000 (19:44 +0000)
committerbors <bors@rust-lang.org>
Wed, 19 Nov 2014 19:44:20 +0000 (19:44 +0000)
* `set -e` (script should crash on first error)
* detect darwin if running not on travis (and `PLATFORM` and `TRAVIS_OS_NAME` variables are unset)


Trivial merge