Replaced assertJump, assertRevert and expectThrow with shouldFail. (#1363)

* Replaced assertJump, assertRevert and expectThrow with shouldFail.

* Fixed linter errors.

* Fixed typo.

* Made the helpers async.

test/helpers/shouldFail.js

@@ -0,0 +1,31 @@
+const should = require('chai')
+  .should();
+
+async function shouldFailWithMessage (promise, message) {
+  try {
+    await promise;
+  } catch (error) {
+    error.message.should.include(message, 'Wrong failure type');
+    return;
+  }
+
+  should.fail(`Expected '${message}' failure not received`);
+}
+
+async function reverting (promise) {
+  await shouldFailWithMessage(promise, 'revert');
+}
+
+async function throwing (promise) {
+  await shouldFailWithMessage(promise, 'invalid opcode');
+}
+
+async function outOfGas (promise) {
+  await shouldFailWithMessage(promise, 'out of gas');
+}
+
+module.exports = {
+  reverting,
+  throwing,
+  outOfGas,
+};