Debian/Ubuntu dependencies packages list

Please note, in Debian/Ubuntu systems you may need to install the following
packages: libsasl2-dev, python-dev, libldap2-dev, libssl-dev

Update README file

README.md

@@ -41,6 +41,10 @@ packages:
 ```
 $ sudo yum install python-devel openldap-devel
 ```
+Debian/Ubuntu systems may require these packages instead:
+```
+$ sudo apt-get install libsasl2-dev python-dev libldap2-dev libssl-dev
+```
 
 The tool is available in PyPI and can be installed using pip:
 ```