Add README and LICENSE

LICENSE

+The MIT License
+
+Copyright (c) 2015 GitLab, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

+# marketo-tools
+
+This is a simple Sinatra application that receives GitLab.com sign-up hooks and
+passes the relevant information into a Marketo email list.
+
+This replaces our internal [mailchimp-tools] project.
+
+## Relevant issues
+
+- [Point webhook from Mailchimp to Marketo](https://gitlab.com/gitlab-com/www-gitlab-com/issues/427)
+- [Remove nl-importer.gitlap.com](https://dev.gitlab.org/cookbooks/chef-repo/issues/316)
+  (internal)
+
+## Development
+
+## Deployment
+
+## License
+
+Copyright © 2015 GitLab, Inc. It is free software, and may be redistributed
+under terms specified in the [`LICENSE`](LICENSE) file.
+
+[mailchimp-tools]: https://dev.gitlab.org/gitlab/mailchimp-tools