Updated install docs to install pip using setuptools

docs/installation/netbox.md

@@ -5,13 +5,15 @@
 Python 3:
 
 ```no-highlight
-# apt-get install -y python3 python3-dev python3-pip libxml2-dev libxslt1-dev libffi-dev graphviz libpq-dev libssl-dev zlib1g-dev
+# apt-get install -y python3 python3-dev python3-setuptools libxml2-dev libxslt1-dev libffi-dev graphviz libpq-dev libssl-dev zlib1g-dev
+# easy_install3 pip
 ```
 
 Python 2:
 
 ```no-highlight
-# apt-get install -y python2.7 python-dev python-pip libxml2-dev libxslt1-dev libffi-dev graphviz libpq-dev libssl-dev zlib1g-dev
+# apt-get install -y python2.7 python-dev python-setuptools libxml2-dev libxslt1-dev libffi-dev graphviz libpq-dev libssl-dev zlib1g-dev
+# easy_install pip
 ```
 
 **CentOS**
@@ -22,14 +24,14 @@ Python 3:
 # yum install -y epel-release
 # yum install -y gcc python34 python34-devel python34-setuptools libxml2-devel libxslt-devel libffi-devel graphviz openssl-devel redhat-rpm-config
 # easy_install-3.4 pip
-# ln -s -f python3.4 /usr/bin/python
 ```
 
 Python 2:
 
 ```no-highlight
 # yum install -y epel-release
-# yum install -y gcc python2 python-devel python-pip libxml2-devel libxslt-devel libffi-devel graphviz openssl-devel redhat-rpm-config
+# yum install -y gcc python2 python-devel python-setuptools libxml2-devel libxslt-devel libffi-devel graphviz openssl-devel redhat-rpm-config
+# easy_install pip
 ```
 
 You may opt to install NetBox either from a numbered release or by cloning the master branch of its repository on GitHub.
@@ -97,6 +99,9 @@ Python 2:
 # pip install -r requirements.txt
 ```
 
+!!! note
+    If you encounter errors while installing the required packages, check that you're running a recent version of pip (v9.0.1 or higher) with the command `pip -V` or `pip3 -V`.
+
 ### NAPALM Automation
 
 As of v2.1.0, NetBox supports integration with the [NAPALM automation](https://napalm-automation.net/) library. NAPALM allows NetBox to fetch live data from devices and return it to a requester via its REST API. Installation of NAPALM is optional. To enable it, install the `napalm` package using pip or pip3: