It turned out that the tip-of-tree chromium fails to start on Travis
because of two reasons:
- inability to run LinuxSUIDSandbox
- libnss3 library version being too small
Both problems happen because of the outdated "trusty" distribution
which is used on travis.
This patch:
- reverts the previous patch 9e6f779. Instead of introducing such
a weird "api", both phantom_shim/runner.js and test/test.js no
explicitly pass '--no-sandbox' flag to the browser
- updates the libnss3 lib on travis
Fixes#33
