Move notes to the Postgres database

src/main/resources/db/migration/postgresql/V0.2__note.sql

@@ -0,0 +1,11 @@
+CREATE TABLE note(
+    id serial NOT NULL,
+    receiver text NOT NULL,
+    sender text NOT NULL,
+    message text NOT NULL,
+    timestamp bigint NOT NULL,
+    fame smallint NOT NULL,
+    deleted smallint NOT NULL,
+    PRIMARY KEY (id)
+);
+GRANT SELECT, INSERT, UPDATE ON note TO ${server-username};