Add continuous integration for the terraform provider

[ddelnano]

There have been previous attempts to address issues with the test suite (most notably #129, #188, #218). These errors have been exacerbated by the fact that I run the acceptance tests while connected to the Vates VPN. The Vates team recently created a Jenkins instance in their lab environment and when testing with that I noticed that the above issues do not occur. This is likely because the payloads sent from the XO api are large and the go tests were timing out because the network was being saturated in addition to the VPN's CPU load.

Since the Jenkins instance on the lab environment has been stable, the goal of this issue is to enable CI for the following situations:

• Nightly master branch builds
• Testing for pull requests
  • Provide commit status and build logs
• Testing across terraform versions
• Testing across OpenTofu versions