Refactor test infrastructure (#2432)

* use subclass of unittest.TestCase for all test cases

* allow to run single test file (eg. python tools/integration_tests.py)

* test filtering (via --pattern/-p CLI flag)

* use common CLI parser for all tests:
  usage: test.py [-h] [--failfast] [--verbose] [--executable EXECUTABLE]
               [--release] [--pattern PATTERN] [--build-dir BUILD_DIR]

  optional arguments:
  -h, --help            show this help message and exit
  --failfast, -f        Stop on first failure
  --verbose, -v         Verbose output
  --executable EXECUTABLE
                        Use external executable of Deno
  --release             Test against release executable
  --pattern PATTERN, -p PATTERN
                        Run tests that match provided pattern
  --build-dir BUILD_DIR
                        Deno build directory

* respect NO_COLOR variable

tools/repl_test.py

@@ -4,18 +4,10 @@ from subprocess import CalledProcessError, PIPE, Popen
 import sys
 import time
 
-from util import DenoTestCase, test_main
+from test_util import DenoTestCase, run_tests
 
 
 class TestRepl(DenoTestCase):
-    def __init__(self, *args, **kwargs):
-        super(TestRepl, self).__init__(*args, **kwargs)
-        self._warm_up()
-
-    def _warm_up(self):
-        # This may output an error message about the history file (ignore it).
-        self.input("")
-
     def input(self, *lines, **kwargs):
         exit_ = kwargs.pop("exit", True)
         sleep_ = kwargs.pop("sleep", 0)
@@ -141,4 +133,4 @@ class TestRepl(DenoTestCase):
 
 
 if __name__ == "__main__":
-    test_main()
+    run_tests()