Move frontend tests out of zerver/tests/.

This fixes an unfortunate bug where the backend tests in
zerver/tests.py were not being run automatically, and also makes these
a bit easier to find.

frontend_tests/casperjs/samples/cliplay.js

@@ -0,0 +1,24 @@
+/*jshint strict:false*/
+/*global CasperError console phantom require*/
+
+var casper = require("casper").create();
+var dump = require("utils").dump;
+
+// removing default options passed by the Python executable
+casper.cli.drop("cli");
+casper.cli.drop("casper-path");
+
+if (casper.cli.args.length === 0 && Object.keys(casper.cli.options).length === 0) {
+    casper
+        .echo("Pass some args and options to see how they are handled by CasperJS")
+        .exit(1)
+    ;
+}
+
+casper.echo("Casper CLI passed args:");
+dump(casper.cli.args);
+
+casper.echo("Casper CLI passed options:");
+dump(casper.cli.options);
+
+casper.exit();