Small changes to links and add gitter

CONTRIBUTING.md

@@ -9,8 +9,8 @@ Conference presentation on the topic
 [presentation](https://wiki.galaxyproject.org/Documents/Presentations/GCC2013?action=AttachFile&do=view&target=BakerContribute.pdf)). For
 information on contributing more broadly to the Galaxy ecosystem and a
 deeper discussion of some of these points - please see the
-[Develop](https://wiki.galaxyproject.org/Develop/) section of the
-[Galaxy Wiki](https://wiki.galaxyproject.org/).
+[Develop](https://galaxyproject.org/develop) section of the
+[Galaxy Community Hub](https://galaxyproject.org).
 
 ## Before you Begin
 
@@ -23,8 +23,8 @@ comment on it. We also maintain a [tag](https://github.com/galaxyproject/galaxy/
 smaller issues we believe would make the best entry points for new
 developers.
 Galaxy developers are generally available via
-[IRC](https://wiki.galaxyproject.org/GetInvolved#IRC_Channel) and on
-the [development mailing list](http://dev.list.galaxyproject.org/).
+[IRC](https://galaxyproject.org/get-involved), [Gitter](https://gitter.im/galaxyproject/Lobby)
+and on the [development mailing list](http://dev.list.galaxyproject.org).
 
 ## Reporting a new issue
 
@@ -74,13 +74,13 @@ opened using [this form](https://github.com/galaxyproject/galaxy/issues/new).
 
 * If your changes modify code - please ensure the resulting files
   conform to Galaxy [style
-  guidelines](https://wiki.galaxyproject.org/Develop/BestPractices).
+  guidelines](https://galaxyproject.org/develop/best-practices).
 
 * Galaxy contains hundreds of tests of different types and complexity
   and running each is difficult and probably not reasonable at this
   time (someday we will provide a holistic test procedure to make this
   possible). For now, please just review the [running tests
-  documentation](https://wiki.galaxyproject.org/Admin/RunningTests)
+  documentation](https://galaxyproject.org/admin/running-tests)
   and run any that seem relevant. Developers reviewing your pull
   request will be happy to help guide you to running the most relevant
   tests as part of the pull request review process and may request the
@@ -109,11 +109,10 @@ opened using [this form](https://github.com/galaxyproject/galaxy/issues/new).
 ## A Quick Note about Tools
 
   For the most part, Galaxy tools should be published to the
-  [Tool Shed](https://wiki.galaxyproject.org/ToolShed) and not in this
+  [Tool Shed](https://galaxyproject.org/toolshed) and not in this
   repository directly. If you are looking to supply fixes for migrated
   core tools that used to exist in this repository - please checkout
-  the [tools-devteam](https://github.com/galaxyproject/tools-devteam)
+  the [tools-devteam](https://github.com/galaxyproject/tools-iuc)
   repository on GitHub.
 
-  More information about tool development can be found [on the
-  wiki](https://wiki.galaxyproject.org/Develop).
+  More information about tool development can be found [on the comunity hub](https://galaxyproject.org/develop).