Added release script.

release.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+set -e
+
+version=$1
+
+if [ -z "$version" ]; then
+  echo "No version passed! Example usage: ./release.sh 1.0.0"
+  exit 1
+fi
+
+echo "Running tests..."
+go test ./...
+
+echo "Update version..."
+sed -i.bak 's/fmt\.Println("v[0-9]*\.[0-9]*\.[0-9]*")/fmt.Println("v'$version'")/' captain/cmd.go
+rm captain/cmd.go.bak
+
+echo "Build binary..."
+make b
+
+echo "Update repository..."
+git add captain/cmd.go
+git commit -m "Preparing version ${version}"
+git tag --message="v$version" "v$version"
+
+echo "v$version tagged."
+echo "Now, run 'git push origin master && git push --tags' and publish the release on GitHub."