This patch refactors installation tests. With this
refactoring:
- each test is a separate file
- to run a single test, just run the bash file
* tests support optional `--no-build` flag to re-use previously
built packages.
* tests support optional `--debug` flag to see line-by-line test output
* failed tests print a line that can be copied-and-pasted locally
to debug the test
- run all tests with `//installation-tests/run_all_tests.sh`
* test output is hidden for successful runs when run locally and is
shown when test fails
* runs all tests, and reports failed tests in the end
* command output is split into groups when viewed on Github.
