README.md describes automated install

based on jrl-umi3218/Tasks#7

README.md

@@ -107,7 +107,33 @@ abi(M, H, I)                 | `sva::ABInertia(M, H, I)`
 Installing
 ------
 
-### Manual
+### Ubuntu 14.04 and 16.04 binary ppa install
+
+Use the [multi-contact-unstable](https://launchpad.net/~pierre-gergondet+ppa/+archive/ubuntu/multi-contact-unstable) ppa:
+```bash
+sudo add-apt-repository ppa:pierre-gergondet+ppa/multi-contact-unstable
+sudo apt-get update
+sudo apt-get install spacevecalg
+```
+
+### Homebrew OS X install
+
+Install from the command line using [Homebrew](brew.sh):
+
+```bash
+# install homebrew package manager
+ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
+# install caskroom application manager
+brew install caskroom/cask/brew-cask
+# tap homebrew-science package repository
+brew tap homebrew/science
+# tap ahundt-robotics repository
+brew tap ahundt/robotics
+# install tasks and all its dependencies
+brew install spacevecalg
+```
+
+## Manually build from source
 
 #### Dependencies