Support setting action concurrency in manifest

[alexkli]

Describe the solution you'd like

Be able to set concurrency limit of an action in the manifest.yml.

Probably add here: https://github.com/adobe/aio-cli-plugin-runtime/blob/master/src/runtime-helpers.js#L463-L468

Describe alternatives you've considered
No alternatives, other than manually setting it using wsk after deployment through aio, which is a fragile and complicated process.

Additional context
Being able to set a different concurrency than the default 200 in Adobe IO Runtime is important for many use cases.

Looks like it's not possible in wskdeploy yet, only wsk: apache/openwhisk-wskdeploy#1062

The manifest spec does not include it either. Note that concurrentActivations is a different limit.

[alexkli]

I might be able to provide a PR later this week.

[meryllblanchet]

Thanks for the proposal @alexkli ! Looking forward to the PR then :)

Note, as we are refactoring both Runtime and App plugins to simplify the underlying dependencies, the PR might be a better fit for https://github.com/adobe/aio-lib-runtime.

Could you sync-up with @purplecabbage and @Himavanth before?

[aiojbot]

JIRA issue created: https://jira.corp.adobe.com/browse/ACNA-829

[alexkli]

@meryllblanchet @purplecabbage @Himavanth PR ready here: #177

I leave the refactoring to you. The current aio still uses the runtime-helpers.js from https://github.com/adobe/aio-cli-plugin-runtime, so that was the only way to build and test this change.