docs(readme): make pull of cached layers to speed make build

Author: Gabriel Monroy

Makefile

@@ -10,6 +10,9 @@ all: build run
 test_client:
 	python -m unittest discover client.tests
 
+pull:
+	vagrant ssh -c 'for c in $(COMPONENTS); do docker pull deis/$$c; done'
+
 build:
 	vagrant ssh -c 'cd share && for c in $(COMPONENTS); do cd $$c && docker build -t deis/$$c . && cd ..; done'
 

README.md

@@ -28,9 +28,10 @@ export FLEETCTL_TUNNEL=172.17.8.100
 
 ## Build Deis
 
-Use `make build` to assemble all of the Deis components from Dockerfiles.  Grab some coffee while it builds the images on the CoreOS VM (it can take a while).
+Use `make pull` to download cached layers from the public Docker Index.  Then use `make build` to assemble all of the Deis components from Dockerfiles.  Grab some coffee while it builds the images on the CoreOS VM (it can take a while).
 
 ```
+make pull
 make build
 ```