Add 'nothing' matcher and tests

src/core/matchers/nothing.js

@@ -0,0 +1,20 @@
+getJasmineRequireObj().nothing = function() {
+  /**
+   * {@link expect} nothing explicitly.
+   * @function
+   * @name matchers#nothing
+   * @example
+   * expect().nothing();
+   */
+  function nothing() {
+    return {
+      compare: function() {
+        return {
+          pass: true
+        };
+      }
+    };
+  }
+
+  return nothing;
+};