Scott Barta's solution worked for me, except I had to add these to the dependencies of my main project build.gradle file:
compile files('libs/android-support-v4.jar')
compile project(':libraries:facebook')
Also worth mentioning, you need to make sure:
android {
compileSdkVersion 18
buildToolsVersion "18.1.1"
defaultConfig {
minSdkVersion 7
targetSdkVersion 18
}
Are the same in both build.gradle files...Once i did this it ran like a charm.