move messages to mail (#56)

mail/README.md

@@ -0,0 +1,49 @@
+The mail service is a simplified service for sending mail, much like email.
+
+# Mail Service
+
+## Send a message
+
+### CLI
+
+```bash
+> micro mail send --to=John --from=Barry --subject=HelloWorld --text="Hello John"
+```
+
+## List the mail a user has received
+
+### CLI
+
+```bash
+> micro mail list --user=John
+{
+	"mail": [
+		{
+			"id": "78efd836-ca51-4163-af43-65985f7c6587",
+			"to": "John",
+			"from": "Barry",
+			"subject": "HelloWorld",
+			"text": "Hello John",
+			"sent_at": "1602777240"
+		}
+	]
+}
+```
+
+## Lookup an individual email by ID
+
+### CLI
+
+```bash
+> micro mail read --id=78efd836-ca51-4163-af43-65985f7c6587
+{
+	"message": {
+		"id": "78efd836-ca51-4163-af43-65985f7c6587",
+		"to": "John",
+		"from": "Barry",
+		"subject": "HelloWorld",
+		"text": "Hello John",
+		"sent_at": "1602777240"
+	}
+}
+```