Update CircleCI V2 API support

This change includes an updated buildevents binary, fixing the watch command's use of the CircleCI API.

Updated CircleCI API, support for parallel jobs

This change includes an updated buildevents binary, fixing the watch command's use of the CircleCI API. It also makes the orb useful for tests that use parallelism. Previously, parallel tests would all produce the same span IDs causing a conflict in the resulting trace. This version adds the ID of the parallel node worker to the span ID allowing multiple workers on the same job to peacefully coexist.

Bump buildevents to get longer watch timeout

New in this release - the watch command of buildevents will wait up to 2 minutes before declaring a build complete when there are still outstanding jobs.

Use cache instead of workspace to store buildevents executables

For projects using a workspace to communicate artifacts between jobs, our use of the workspace to store our executables means that we're doubling a potentially long time spent attaching to the workspace (once to grab our executables, once for project to attach.)

Instead, store buildevents in a versioned cache. This should result in a build speedup that scales with the size of your workspace.

Support non-libc environments on linux

Updates the version of buildevents to 0.4.4. This version is statically linked and shouldn't require the system be based around libc.

Bugfix release

Updates to buildevents v0.4.1 containing a bug fix in the cmd command.

Add extra content to the trace, bugfixes

This change includes a new command add_context that lets you add additional fields to the spans sent representing each job. Uses include any additional data you would like to send about the build from job parameters to untraced command's output and artifact sizes.

Additionally, some resilience around polling the CircleCI API for information around the build has been added - retries in the face of some transient errors and confirmation that a build is actually finished.

The README for the repository has been updated with some usage information and additional examples.

Use CircleCI API token for polling private builds

In order to poll the CircleCI when building code from a private github repo, a CircleCI API Token is required. It can be set via the BUILDEVENT_CIRCLE_API_TOKEN environment variable.

Finish traces by watching the CircleCI API

This change adjusts the method by which traces are finished - it uses the watch command in version 0.2 of bulidevents. To reflect the change and make it more clear what is happening, the name of the command has changed.

This is a breaking change - the finish_trace command has been replaced by the watch_build_and_finish command.

Reference specific version of buildevents

In order to use the buildevents orb to make a trace building buildevents itself, it can't reference the latest release because then it tries to download the latest release in order to build the latest release and gets a big fat 404.

Besides, for the sanity of all involved, if you pin a specific version of the orb, you should get a specific version of buildevents or version control becomes insanity.