Original function name in callback meta-data

[ewilde]

Description

Adds original function name in callback meta-data X-Function-Name

Motivation and Context

• I have raised an issue Provide original function name in callback #82 to propose this change (required)

How Has This Been Tested?

Tested on docker swarm:

• Invoke function a (in this example called echo) asynchronously provide callback to function b
• verify header is set

Logs for function b

2019-12-10T21:17:05Z 2019/12/10 21:17:05 stderr: 2019/12/10 21:17:05 Function: [echo], status:[200], time:[0.001863], body:OK

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly see: X-Function-Name meta-data added to async section docs#195.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes.
• All new and existing tests passed.

[LucasRoesler]

Looks good and it works as described 👍

[alexellis]

This branch has conflicts that must be resolved.
Use the command line to resolve conflicts before continuing

👨‍💻

[alexellis]

@ewilde please see my comment.

[ewilde]

@alexellis PTAL, rebased

[alexellis]

LGTM