Stop using $PLACEHOLDER_NAME_TEST_INTEGRATION

Instead, make the integration tests a separate module. You can't run
these tests by accident because they will not run at all when you
`go test` from the top-level directory. You will need to `cd test`
before using `go test` in order to run the integration tests.

Signed-off-by: Ryan Richard <richardry@vmware.com>

test/integration/main_test.go

@@ -1,32 +0,0 @@
-/*
-Copyright 2020 VMware, Inc.
-SPDX-License-Identifier: Apache-2.0
-*/
-
-package integration
-
-import (
-	"fmt"
-	"os"
-	"strconv"
-	"testing"
-)
-
-// force users to opt-in to running the integration tests.
-// this prevents them from running if someone does `go test ./...`
-// these tests could be destructive to the cluster under test.
-const magicIntegrationTestsEnvVar = "PLACEHOLDER_NAME_TEST_INTEGRATION"
-
-var shouldRunIntegrationTests = func() bool {
-	b, _ := strconv.ParseBool(os.Getenv(magicIntegrationTestsEnvVar))
-	return b
-}()
-
-func TestMain(m *testing.M) {
-	if !shouldRunIntegrationTests {
-		fmt.Printf("SKIP: %s=true env var must be explicitly set for integration tests to run\n", magicIntegrationTestsEnvVar)
-		os.Exit(0)
-	}
-
-	os.Exit(m.Run())
-}