[Feature Request] Add build_parameters from CircleCI API

[mcdanielj]

Greetings,

I use the CI plugin to execute a shell script that accomplishes testing and builds.

For projects that are dependencies to other projects it also triggers a rebuild of those branches via the API.

Unfortunately, there are a few cases where only some, but not all, should be built depending on whether or not the build was triggered by a commit or the API.

I checked your reference to the CircleCI API for documentation and it appears to have a method of sending parameters as data in the API call.

My personal use case would just be a boolean flag to test if a build was triggered via a commit or an API call. I'm not sure if anyone could make use of more than that. Possibly?

Ref: https://circleci.com/docs/2.0/env-vars/#injecting-environment-variables-with-api-v1; Injecting Environment Variables with API v1: Example using curl.

Loving GitBucket. Thank you for all your hard work.

./jeremy