refresh contributing guidelines [ci skip]

CONTRIBUTING.md

@@ -3,44 +3,41 @@
 This page describes how to contribute changes to Savon.
 
 Please do not create a pull request without reading this guide first.
-Make sure to read the documentation for your version at [savonrb.com](http://savonrb.com/)
-and post questions to the [mailing list](https://groups.google.com/forum/#!forum/savonrb).
+Make sure to read the documentation for your version and ask questions on [Stack Overflow](https://stackoverflow.com/questions/ask?tags=savon).
 
 **Bug fixes**
 
-If you really think you found a bug, please make sure to add as many information as possible
+If you really think you found a bug, please make sure to add as much information as possible
 to the ticket. You're a developer, we are developers and you know we need tests to reproduce
 problems and make sure they don't come back.
 
 So if you can reproduce your problem in a spec, that would be awesome! If you can't, please
-let us know how we could make this easier for you. Also, provide code and the WSDL of the
+let us know how we can make this easier for you. Also, provide code and the WSDL of the
 service you're working with so others can try to come up with a spec for your problem.
 
 After we have a failing spec, it obviously needs to be fixed. Make sure your new spec is the
 only failing one under the `spec` directory. Travis only runs the "unit tests" at `spec/savon`,
-but Savon actually has with some additional "integration/example specs" at `spec/integration`,
-which you need to run locally to make sure the integration with real world services still works.
+but Savon actually has some additional specs at `spec/integration`, which you need to run locally 
+to make sure the integration with real world services still works.
 
-Notice that these specs are not run by Travis, because the service's are not guaranteed to work
-all the time and the specs will timeout after a few seconds when the service is currently down.
+These specs are not run by Travis, because the services are not guaranteed to work all the time.
 
 Please follow this basic workflow for pull requests:
 
 * [Fork the project](https://help.github.com/articles/fork-a-repo)
 * Create a feature branch and make your bug fix
 * Add tests for it!
-* Update the [Changelog](https://github.com/savonrb/savon/blob/master/CHANGELOG.md)
 * [Send a pull request](https://help.github.com/articles/using-pull-requests)
 * [Check that your pull request passes the build](https://travis-ci.org/savonrb/savon/pull_requests)
 
 
 **Improvements and feature requests**
 
 If you have an idea for an improvement or a new feature, please feel free to
-[create a new issue](https://github.com/savonrb/savon/issues/new) and describe your idea
+[create a new issue](https://github.com/savonrb/savon/issues/new/choose) and describe your idea
 so that other people can give their insights and opinions. This is also important to avoid
 duplicate work.
 
 Pull requests and issues on GitHub are meant to be used to discuss problems and ideas,
-so please make sure to participate and follow up on questions. In case noone comments
+so please make sure to participate and follow up on questions. In case no one comments
 on your ticket, please keep updating the ticket with additional information.