Use PUT verb for function updates and update messages

[johnmccabe]

This PR is part of a group of 3:

• Implement Swarm update handler (and use PUT method for updates) faas#208
• Use PUT verb for function updates and update messages #123
• Use PUT HTTP verb for update endpoint faas-provider#4

Description

This commit switches the verb used for updates from the non-HTTP UPDATE to PUT.

It also updates the message returned from the deploy action depending on whether its a deploy or update:

$ ./faas-cli-darwin deploy -f ./samples.yml --replace=false --update
Updating: ruby-echo.
Updated.
URL: http://localhost:8080/function/ruby-echo

Motivation and Context

• I have raised an issue to propose this change (Implement Swarm update handler (and use PUT method for updates) faas#208)

UPDATE is not a valid HTTP verb, the correct verb to use for updates is PUT (as pointed out by @imeoer - thx!)

How Has This Been Tested?

Tested performing a range of updates on a local swarm, changing envvars etc.

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.
• 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.

[alexellis]

Can we co-ordinate PRs across faas-provider, faas-netes and faas?

[johnmccabe]

@alexellis I've raised PRs in faas/faas-cli and faas-provider - I don't think faas-netes, or any of the integrations need to be changed to pick up the change in verb.

[alexellis]

LGTM