Update docs

README.md

@@ -4,6 +4,36 @@
 - io.grpc:grpc-protobuf
 - io.grpc:grpc-stub
 
+w/ **Gradle**
+```
+compile 'io.grpc:grpc-netty-shaded:' + grpc_java_version
+compile 'io.grpc:grpc-protobuf:' + grpc_java_version
+compile 'io.grpc:grpc-stub:' + grpc_java_version
+```
+
+w/ **Maven**
+```
+<dependency>
+    <groupId>io.grpc</groupId>
+    <artifactId>grpc-netty-shaded</artifactId>
+    <version>${grpc_java_version}</version>
+</dependency>
+<dependency>
+    <groupId>io.grpc</groupId>
+    <artifactId>grpc-protobuf</artifactId>
+    <version>${grpc_java_version}</version>
+</dependency>
+<dependency>
+    <groupId>io.grpc</groupId>
+    <artifactId>grpc-stub</artifactId>
+    <version>${grpc_java_version}</version>
+</dependency>
+```
+
+## Usage
+
+See Javadoc and `src/test/java/bdchain/api/*Tests.java` files.
+
 ## Testing
 
 1. Download [mock servers](https://public.internetapi.cn/?dir=bdchain/test) for Transaction Ledger &