Implement begining of migration

Move Function/Query definition

src/main/kotlin/fr/postgresjson/migration/Query.kt

@@ -0,0 +1,40 @@
+package fr.postgresjson.migration
+
+import fr.postgresjson.connexion.Connection
+
+class Query(
+    private val up: String,
+    private val down: String,
+    private val connection: Connection
+): Migration {
+    enum class Status(i: Int) { OK(2), UP_FAIL(0), DOWN_FAIL(1) }
+
+    override fun up(): Int {
+        connection.exec(up)
+        return 1
+    }
+
+    override fun down(): Int {
+        connection.exec(down)
+        return 1
+    }
+
+    override fun test(): Int {
+        connection.inTransaction {
+            connection.exec(up)
+            connection.exec(down)
+            it.sendQuery("ROLLBACK");
+        }
+        return 1
+    }
+
+    override fun status(): Int {
+        val result = connection.inTransaction {
+            connection.exec(up)
+            connection.exec(down)
+            it.sendQuery("ROLLBACK")
+        }.join()
+
+        return result.rowsAffected.toInt()
+    }
+}