Add toHaveBeenCalledBefore matcher

This matcher makes sure the 'actual' spy is called before the
'expected' spy.

This code has been written in cooperation with Benjamin Van Ryseghem.

src/core/matchers/requireMatchers.js

@@ -15,6 +15,7 @@ getJasmineRequireObj().requireMatchers = function(jRequire, j$) {
       'toContain',
       'toEqual',
       'toHaveBeenCalled',
+      'toHaveBeenCalledBefore',
       'toHaveBeenCalledWith',
       'toHaveBeenCalledTimes',
       'toMatch',