setting-up-your-development-environment.rst: wording, links (#631)

docs/contribute/setting-up-your-development-environment.rst: update links, improve wording.

docs/contribute/setting-up-your-development-environment.rst

@@ -1,4 +1,4 @@
-.. Copyright 2012 splinter authors. All rights reserved.
+.. Copyright © 2018 splinter authors. All rights reserved.
    Use of this source code is governed by a BSD-style
    license that can be found in the LICENSE file.
 
@@ -7,29 +7,29 @@
     :keywords: splinter, open source, python, contribute, development environment
 
 +++++++++++++++++++++++++++++++++++++++++++++++
-Setting up you splinter development environment
+Setting up your splinter development environment
 +++++++++++++++++++++++++++++++++++++++++++++++
 
-Setting up a splinter development environment is a really easy task, you need to make sure you have some
-basic development tools in your machine, you can setup the entire environment with just one command.
+Setting up a splinter development environment is a really easy task. Once you have some
+basic development tools on your machine, you can set up the entire environment with just one command.
 
 Basic development tools
 =======================
 
 Let's deal with those tools first.
 
-Mac OS
+macOS
 ------
 
-If you're a Mac OS user, you just need to install XCode, which can be downloaded
-from Mac App Store (on Mac OS X Lion) or from
-`Apple website <http://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?bundleID=20792>`_.
+If you're a macOS user, you just need to install Xcode, which can be downloaded
+from Mac App Store (on Snow Leopard or later) or from
+`Apple website <https://developer.apple.com/download/>`_.
 
 Linux
 -----
 
-If you are running a Linux in your computer, you need to install some basic development libraries
-and headers. On Ubuntu, you can easily install all of them using ``apt-get``:
+If you are running a Linux distribution, you need to install some basic development libraries
+and headers. For example, on Ubuntu, you can easily install all of them using ``apt-get``:
 
 .. highlight:: bash
 
@@ -41,15 +41,15 @@ PIP and virtualenv
 ------------------
 
 Make sure you have pip installed. We manage all splinter development dependencies with
-`PIP <http://pip-installer.org>`_, so you should use it for too.
+`PIP <https://pip.pypa.io/en/stable/>`_, so you should use it too.
 
-And please, for the sake of a nice development environment, use `virtualenv <http://virtualenv.org>`_.
+And please, for the sake of a nice development environment, use `virtualenv <https://pypi.org/project/virtualenv/>`_.
 If you aren't using it yet, start now. :)
 
 Dependencies
 ------------
 
-Once you had all development libraries installed for you OS, just install all splinter development dependencies with
+Once you have all development libraries installed for your OS, just install all splinter development dependencies with
 ``make``:
 
 .. highlight:: bash