Extract common server encryption logic (#65)

* refactor: extract common message encryption logic
* refactor: move letsencrypt logic to common
* refactor: rename common package to encryption
* test: add encryption tests

encryption/encryption_suite_test.go

@@ -0,0 +1,13 @@
+package encryption_test
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+func TestManagement(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Management Service Suite")
+}