Add release script

Signed-off-by: Ben Firshman <ben@firshman.co.uk>

Dockerfile

@@ -1,5 +1,6 @@
 FROM golang:1.3-cross
 RUN go get github.com/mitchellh/gox
+RUN go get github.com/aktau/github-release
 ENV GOPATH /go/src/github.com/docker/machine/Godeps/_workspace:/go
 WORKDIR /go/src/github.com/docker/machine
 ADD . /go/src/github.com/docker/machine

script/build

@@ -1,4 +1,5 @@
 #!/bin/sh
 set -e
+rm -f machine_*
 docker build -t docker-machine .
 exec docker run --rm -v `pwd`:/go/src/github.com/docker/machine docker-machine gox -os="darwin linux windows"

script/release

@@ -0,0 +1,32 @@
+#!/bin/bash
+set -e
+if [ -z "$1" ]; then
+    echo "Pass the version number as the first arg. E.g.: script/release 1.2.3"
+    exit 1
+fi
+VERSION=$1
+if [ -z "$GITHUB_TOKEN" ]; then
+    echo "GITHUB_TOKEN must be set for github-release"
+    exit 1
+fi
+
+script/build
+git tag $VERSION
+git push --tags
+docker run --rm -e GITHUB_TOKEN docker-machine github-release release \
+    --user docker \
+    --repo machine \
+    --tag $VERSION \
+    --name $VERSION \
+    --description "" \
+    --pre-release \
+for BINARY in machine_*; do
+    docker run --rm -e GITHUB_TOKEN -v `pwd`:/go/src/github.com/docker/machine \
+        docker-machine github-release upload \
+        --user docker \
+        --repo machine \
+        --tag $VERSION \
+        --name $BINARY \
+        --file $BINARY
+done
+