Install CDP client after Python on macOS

Install the CDP CLI client and verify if it is working.

Use the following command to install the CDP client:
```
$ pip3 install cdpcli --user
```
After you install the CDP client, add the Python directory that contains the client executable files to the PATH environment variable.
The directory can vary based on where Python is installed. For example, for Python 3.6.x the executable files are in the following directory:
```
~/Library/Python/3.6/bin
```
Use the following command to verify that the CDP client is correctly installed:
```
cdp --version
```
To upgrade the CDP client to the latest version, run the following command:
```
$ pip3 install cdpcli --upgrade --user
```