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Both problems happen because of the outdated "trusty" distribution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

.travis.yml

@@ -3,7 +3,6 @@ node_js:
   - "7"
 dist: trusty
 env:
-  - DISABLE_CHROMIUM_SANDBOX=true
 cache:
   yarn: true
   directories:

lib/Browser.js

@@ -51,8 +51,6 @@ class Browser {
                 `--disable-gpu`,
             ]);
         }
-        if (process.env['DISABLE_CHROMIUM_SANDBOX'])
-            this._chromeArguments.push('--no-sandbox');
         if (typeof options.executablePath === 'string') {
             this._chromeExecutable = options.executablePath;
         } else {

phantom_shim/runner.js

@@ -59,6 +59,7 @@ if (!fs.existsSync(scriptPath)) {
 var browser = new Browser({
         remoteDebuggingPort: 9229,
         headless: argv.headless,
+        args: ['--no-sandbox']
 });
 
 var context = createPhantomContext(browser, scriptPath, argv);

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();
     });