Update proto for minor change (milvus-io#290)

Signed-off-by: groot <[email protected]>

DEVELOPMENT.md

@@ -7,34 +7,42 @@ This document will help to setup your development environment and running tests
     -   Java 8 or higher
     -   Apache Maven
 
-## Building Milvus java SDK
-fetch proto files from submodule project
+### Clone the code
+
 ```shell
-  git submodule update --init
+$ git clone --recursive [email protected]:milvus-io/milvus-sdk-java.git
 ```
 
-call the following command to generate protobuf related code
+Milvus proto files are managed by a submodule project under the directory: src/milvus-proto
+Fetch Milvus proto files by the following command(If the previous clone is not with submodules)
+```shell
+$ git submodule update --init
+```
+
+## Building Milvus java SDK
+
+Call the following command to generate protobuf related code
 ```shell
-  mvn install
+$  mvn install
 ```
 
 ## Update Milvus proto files
-Milvus proto files are managed by a submodule project under the directory: src/main/milvus-proto
+Milvus proto files are managed by a submodule project under the directory: src/milvus-proto
 Before developing new interfaces, you need to get the latest proto files by the following command:
 ```shell
-  git submodule update --remote
+$  git submodule update --remote
 ```
 
 ## Building Milvus
-see detailed information at:
+See detailed information at:
 https://github.com/milvus-io/milvus/blob/master/DEVELOPMENT.md
 
 ## Start a Milvus cluster
 You need to start a latest milvus cluster to test the java SDK, see instructions at:
 https://milvus.io/docs/v2.0.0/install_standalone-docker.md
 
 ### Unit Tests
-All unit test is under director src/test, TBD
+All unit test is under director src/test
 
 ## GitHub Flow
 Milvus SDK repo follows the same git work flow as milvus main repo, see