update docs + missing install instructions

[niftylettuce]

users need to add this to build.gradle

compile 'com.google.android.gms:play-services-location:10.0.1'

and the docs are not accurate for latest version of RN

not sure if you have time, would be appreciated for others if you updated

thank you

[pewh]

Have you test this library with latest RN version? I follow the instruction in README & modify MainApplication.java to up-to-date way, but still failed.

    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
        new MainReactPackage(),
        ...
        new AndroidGeolocationPackage(),

Error:

:app:compileDebugJavaWithJavac - is not incremental (e.g. outputs have changed, no previous execution, etc.).
~/foobar/android/app/src/main/java/com/gokuliner/MainApplication.java:13: error: package com.rnandroidgeolocation does not exist
import com.rnandroidgeolocation.AndroidGeolocationPackage;