Add prerequisites to the dependency management doc (fixes issue ResearchKit#1184)

Author: bgannin

docs-standalone/dependency-management.md

@@ -3,6 +3,15 @@ Dependency Management
 
 The ResearchKit framework can also be added to your app using CocoaPods or Carthage.
 
+Prerequisites
+------------
+
+* [Git](https://www.git-scm.com) 2.19 or later (`git --version`)
+* [Git-LFS](https://git-lfs.github.com) 2.4.2 or later (`git-lfs --version`)
+* [CocoaPods](https://cocoapods.org) 1.0 or later (`pod env --version`)
+* [Carthage](https://github.com/Carthage/Carthage) 0.30 or later (`carthage version`)
+
+
 Installation with CocoaPods
 ------------
 Add the following line to your [Podfile](http://guides.cocoapods.org/syntax/podfile.html) and run `pod install`: