add test script for testing

Signed-off-by: Corbin Halliwill <challiwill@pivotal.io>

scripts/ci

@@ -0,0 +1,18 @@
+#!/bin/bash
+# vim: set ft=sh
+
+set -eu
+
+export GOPATH=$PWD/gopath
+export PATH=$GOPATH/bin:$PATH
+
+cd $GOPATH/src/github.com/concourse/github-release-resource
+
+export GOPATH=${PWD}/Godeps/_workspace:$GOPATH
+export PATH=${PWD}/Godeps/_workspace/bin:$PATH
+
+go install github.com/onsi/ginkgo/ginkgo
+
+CGO_ENABLED=1 ginkgo -race -r -p "$@"
+
+./scripts/build

scripts/test

@@ -1,18 +1,18 @@
 #!/bin/bash
-# vim: set ft=sh
 
-set -eu
+set -e
 
-export GOPATH=$PWD/gopath
-export PATH=$GOPATH/bin:$PATH
+not_installed() {
+  ! command -v $1 > /dev/null 2>&1
+}
 
-cd $GOPATH/src/github.com/concourse/github-release-resource
+github_release_resource_dir=$(realpath $(dirname $(dirname $0)))
 
-export GOPATH=${PWD}/Godeps/_workspace:$GOPATH
-export PATH=${PWD}/Godeps/_workspace/bin:$PATH
+if not_installed ginkgo; then
+  echo "# ginkgo is not installed! run the following command:"
+  echo "    go install github.com/onsi/ginkgo/ginkgo"
+  exit 1
+fi
 
-go install github.com/onsi/ginkgo/ginkgo
-
-CGO_ENABLED=1 ginkgo -race -r -p "$@"
-
-./scripts/build
+cd $github_release_resource_dir
+ginkgo -r -p