Current behavior (how does the issue manifest):
The lambda invoke activity returns a value object which includes the payload and the []byte serialized response. This really has no real purpose and causes confusion between the unmarshaled payload in the return param result .

Expected behavior:
Remove the value param, as both the unmarshaled payload and the status are both returned in separate params already, no need to keep a struct of the raw return data.

Minimal steps to reproduce the problem (not required if feature enhancement):

Please tell us about your environment (Operating system, docker version, browser & web ui version, etc):

Flogo version (CLI & contrib/lib. If unknown, leave empty or state unknown): 0.X.X

Additional information you deem important (e.g. issue happens only occasionally):