stdlib/bats: implemented integration tests

Signed-off-by: Sam Alba <samalba@users.noreply.github.com>

stdlib/bats/tests/testfile/test.bats

@@ -0,0 +1,12 @@
+setup() {
+    load 'node_modules/bats-support/load'
+    load 'node_modules/bats-assert/load'
+}
+
+@test "simple bats test" {
+    run echo "Hello world"
+    assert_success
+
+    run cat /do/not/exist
+    assert_failure
+}