Feature/dynamic return values

[jlou2u]

Summary

Adds RunWithReturn which is essentially Run but adds Arguments as the return type and propagates them.

Used this as a starting point #742

Changes

• Adds RunWithReturn

Motivation

Helps write simple tests that can dynamically calculate return values.

Example (from test)

counter := 0
mockedService.On("TheExampleMethod", Anything, Anything, Anything).
	RunWithReturn(func(args Arguments) Arguments {
		counter++
		a, b, c := args[0].(int), args[1].(int), args[2].(int)
		assert.IsType(t, 1, a)
		assert.IsType(t, 1, b)
		assert.IsType(t, 1, c)
		return Arguments{counter}
	}).
	Twice()

answer, _ := mockedService.TheExampleMethod(2, 4, 5)
assert.Equal(t, 1, answer)

answer, _ = mockedService.TheExampleMethod(44, 4, 5)
assert.Equal(t, 2, answer)

Related issues

#742