[Fix] The most recent changes to golang/protobuf breaks the spew Circ…

…ular data structure detection

The latest update to golang/protobuf (I am on v1.4.2) break the spew circular data structure detection. This means that when calling `assert.Equal(t, proto1, proto2)` will not only fail, but also enter an infinite recursion.

Given spew is not being actively maintained, and tesitfy should set some upper bound, we need to set a `MaxDepth` to some very high number, so at least the test will not run for a very long time and finish and fail quickly.

assert/assertions.go

@@ -1622,6 +1622,7 @@ var spewConfig = spew.ConfigState{
 	DisableCapacities:       true,
 	SortKeys:                true,
 	DisableMethods:          true,
+	MaxDepth:                100,
 }
 
 type tHelper interface {