Fix Travis-Ci tests

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Both problems happen because of the outdated "trusty" distribution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

test/test.js

@@ -31,7 +31,7 @@ describe('Puppeteer', function() {
     var page;
 
     beforeAll(function() {
-        browser = new Browser();
+        browser = new Browser({args: ['--no-sandbox']});
         staticServer = new StaticServer(path.join(__dirname, 'assets'), PORT);
         GoldenUtils.removeOutputDir();
     });