[docs] Remove references to manual submodule initialization

platform/android/CONTRIBUTING_LINUX.md

@@ -32,13 +32,11 @@ gradle will take the value of the `MAPBOX_ACCESS_TOKEN` environ variable and sav
 
 ## Building
 
-Checking out the code and initializing the git submodules:
+Checking out the code:
 
 ```
 $ git clone https://github.com/mapbox/mapbox-gl-native.git
 $ cd mapbox-gl-native
-$ git submodule init
-$ git submodule update
 ```
 
 Building a debug version will generated a self-signed test application that can be installed on the phone or emulator:

platform/ios/DEVELOPING.md

@@ -81,13 +81,6 @@ To add or update text that the user may see in the iOS SDK:
 
 `make test-ios` builds and runs unit tests of cross-platform code as well as the SDK.
 
-Before you can run UI tests of the SDK, check out KIF and OHHTTPStubs via Git submodules:
-
-```bash
-git submodule init
-git submodule update
-```
-
 Before you can run unit tests of the cross-platform code on the command line, install ios-sim version 3.2.0 (not any other version):
 
 ```bash

platform/node/README.md

@@ -11,13 +11,13 @@ By default, installs binaries. On these platforms no additional dependencies are
 - 64 bit OS X or 64 bit Linux
 - Node.js v4.x _(note: v5+ is known to have issue)_
 
-Just run:
+Run:
 
 ```
 npm install mapbox-gl-native
 ```
 
-Other platforms will fall back to a source compile with `make node`. To compile this module, make sure all submodules are initialized with `git submodule update --init` and install the [external dependencies required to build from source](https://github.com/mapbox/mapbox-gl-native/blob/node-v2.1.0/INSTALL.md#2-installing-dependencies).
+Other platforms will fall back to a source compile with `make node`; see INSTALL.md in the repository root directory for prequisites.
 
 ## Testing