add quickstart 4 examples (#26)

* init quickstart 4

* fix Op indentation

* update packages

quickstart/4-composing-services-with-aqua/adder/src/main.rs

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2021 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use marine_rs_sdk::{marine, module_manifest, WasmLoggerBuilder};
+
+module_manifest!();
+
+pub fn main() {
+    WasmLoggerBuilder::new().build().unwrap();
+}
+
+#[marine]
+pub fn add_one(value: u64) -> u64 {
+    value + 1
+}
+
+#[cfg(test)]
+mod tests {
+    use marine_rs_sdk_test::marine_test;
+
+    #[marine_test(config_path = "../Config.toml", modules_dir = "../artifacts")]
+    fn test_greeting(adder: marine_test_env::adder::ModuleInterface) {
+        let value = 5;
+        let res = adder.add_one(value);
+        assert_eq!(value + 1, res);
+    }
+}