refactor: remove dependency on watchman

Instead of using FB's watchman library to monitor FS changes in watch
commands, we now use the pure-JS library chokidar.

bin/bootstrap-osx

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 # install/update homebrew dependencies
-BREW_DEPS="cmake git kubectl kubernetes-helm stern rsync watchman icu4c pkg-config"
+BREW_DEPS="cmake git kubectl kubernetes-helm stern rsync icu4c pkg-config"
 
 brew update
 brew install ${BREW_DEPS}

docs/introduction/getting-started.md

@@ -49,7 +49,6 @@ You need the following dependencies on your local machine to use Garden:
 * [Docker](https://docs.docker.com/)
 * Git
 * rsync
-* [Watchman](https://facebook.github.io/watchman/docs/install.html)
 * [Helm](https://github.com/kubernetes/helm)
 * Local installation of Kubernetes and kubectl
 
@@ -62,8 +61,7 @@ For local Kubernetes, you can use [Minikube](https://github.com/kubernetes/minik
 
 #### Step 3: Install other dependencies
 
-Use your preferred method or package manager to install `node` (version 8.x or higher), `git`, `rsync`, 
-[Watchman](https://facebook.github.io/watchman/docs/install.html) and
+Use your preferred method or package manager to install `node` (version 8.x or higher), `git`, `rsync` and
 [Helm](https://github.com/kubernetes/helm).
 
 #### Step 4: Install `garden-cli`