Reorder installation steps for paddledet in docs/tutorials/INSTALL.md (#4588)

Reorder installation steps for paddledet in docs/tutorials/INSTALL.md 

docs/tutorials/INSTALL.md

@@ -77,13 +77,13 @@ python -c "import paddle; print(paddle.__version__)"
 cd <path/to/clone/PaddleDetection>
 git clone https://github.com/PaddlePaddle/PaddleDetection.git
 
-# Compile and install paddledet
-cd PaddleDetection
-python setup.py install
-
 # Install other dependencies
+cd PaddleDetection
 pip install -r requirements.txt
 
+# Compile and install paddledet
+python setup.py install
+
 ```
 
 **Note**
@@ -103,9 +103,9 @@ python ppdet/modeling/tests/test_architectures.py
 If the tests are passed, the following information will be prompted:
 
 ```
-.....
+.......
 ----------------------------------------------------------------------
-Ran 5 tests in 4.280s
+Ran 7 tests in 12.816s
 OK
 ```
 

docs/tutorials/INSTALL_cn.md

@@ -70,10 +70,10 @@ cd <path/to/clone/PaddleDetection>
 git clone https://github.com/PaddlePaddle/PaddleDetection.git
 
 # 安装其他依赖
+cd PaddleDetection
 pip install -r requirements.txt
 
 # 编译安装paddledet
-cd PaddleDetection
 python setup.py install
 ```
 
@@ -96,9 +96,9 @@ python ppdet/modeling/tests/test_architectures.py
 测试通过后会提示如下信息：
 
 ```
-.....
+.......
 ----------------------------------------------------------------------
-Ran 5 tests in 4.280s
+Ran 7 tests in 12.816s
 OK
 ```