* [testing framework] prepare for beta phase of development
* [Testing Framework] Add module block to test run blocks
* [testing framework] allow tests to define and override providers
* testing framework: introduce interrupts for stopping tests
* remove panic handling, will do it properly later
* Add test structure to views package for rendering test output
* Add test file HCL configuration and parser functionality
* Adds a TestContext structure for evaluating assertions against the state and plan
* Add test command to Terraform CLI
