Move to testbed/vim Docker repo (#18)

This also adds a separate Dockerfile for the tests, making the example
work by itself.

Ref: https://hub.docker.com/r/testbed/vim/
Ref: #14

Author: blueyed

Makefile

@@ -1,14 +1,16 @@
-.PHONY: build test
+.PHONY: build push test
 
 build:
-	docker build -t "tweekmonster/vim-testbed" .
+	docker build -t testbed/vim .
 
-# test: build the base image and then the example image on top, running tests
-# therein.
+push:
+	docker push testbed/vim
+
+# test: build the base image and example image on top, running tests therein.
 DOCKER_BASE_IMAGE:=vim-testbed-base
 DOCKER_EXAMPLE_IMAGE:=vim-testbed-example
 test:
 	docker build -t "$(DOCKER_BASE_IMAGE)" . \
 	  && cd example \
-	  && docker build -t "$(DOCKER_EXAMPLE_IMAGE)" . \
+	  && docker build -f Dockerfile.tests -t "$(DOCKER_EXAMPLE_IMAGE)" . \
 	  && make test IMAGE=$(DOCKER_EXAMPLE_IMAGE)

README.md

@@ -1,7 +1,7 @@
 # Vim Testbed
 
 [![Build Status](https://travis-ci.org/tweekmonster/vim-testbed.svg?branch=master)](https://travis-ci.org/tweekmonster/vim-testbed)
-[![](https://badge.imagelayers.io/tweekmonster/vim-testbed:latest.svg)](https://imagelayers.io/?images=tweekmonster/vim-testbed:latest)
+[![](https://badge.imagelayers.io/testbed/vim:latest.svg)](https://imagelayers.io/?images=testbed/vim:latest)
 
 Because unit testing a Vim plugin is a pain in the ass.
 
@@ -29,7 +29,7 @@ your [Docker Hub](https://hub.docker.com/) repository.
 ### Dockerfile
 
 ```Dockerfile
-FROM tweekmonster/vim-testbed:latest
+FROM testbed/vim:latest
 
 RUN install_vim -tag v7.3 -name vim73 -build \
                 -tag v7.4.052 -name vim74 -build \

example/Dockerfile

@@ -1,4 +1,4 @@
-FROM vim-testbed-base
+FROM testbed/vim
 
 RUN install_vim -name vim-precise -tag v7.3.429 -build \
                 -name vim-trusty -tag v7.4.052 -build \

example/Dockerfile.tests

@@ -0,0 +1,8 @@
+# This Dockerfile is used for "make test" from the top level Makefile.
+FROM vim-testbed-base
+
+RUN install_vim -name vim-precise -tag v7.3.429 -build \
+                -name vim-trusty -tag v7.4.052 -build \
+                -name vim-vivid -tag v7.4.488 -build \
+                -name vim-wily -tag v7.4.712 -build \
+                -name vim-xenial -tag v7.4.963 -build