spyOn = function(obj, methodName) {
  return jasmine.getEnv().currentSpec.spyOn(obj, methodName);
}
Function that installs a spy on an existing object's method name.  Used within a Spec to create a spy.

@example
// spy example
var foo = {
  not: function(bool) { return !bool; }
}
spyOn(foo, 'not'); // actual foo.not will not be called, execution stops

@see jasmine.createSpy
@param obj
@param methodName
@return {jasmine.Spy} a Jasmine spy that can be chained with all spy methods