Promote Golang code to the root of the repo

- That's where the code is expected to be
- The only reason the code was buried two directories down was because
  it was originally a BOSH release
- There hasn't been a BOSH release in over two years; last one was Feb
  26, 2022
- Other than a slight adjustment to the relative location of
  `blocklist.txt` file in the integration tests, there were no other
  changes

integration_suite_test.go

@@ -0,0 +1,13 @@
+package main_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestSslipIoDnsServer(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "SslipIoDnsServer Suite")
+}