Remove reference to project board

We haven't been using it to set priorities for a while now.

docs/MAINTAINING.md

@@ -4,7 +4,6 @@ This is a guide/reference for maintainers of the Java track.
 
 - [Your Permissions](#your-permissions)
 - [Maintainer Guides](#maintainer-guides)
-- [The Project Board](#the-project-board)
 - [Miscellaneous](#miscellaneous)
 
 ## Your Permissions 
@@ -27,22 +26,6 @@ As a maintainer, you have write access to three repositories.  "write access" me
 - [exercism.io/docs/getting-involved-in-a-track.md](https://github.com/exercism/exercism.io/blob/master/docs/getting-involved-in-a-track.md)
 - [exercism.io/docs/reviewing-a-pull-request.md](https://github.com/exercism/exercism.io/blob/master/docs/reviewing-a-pull-request.md)
 
-## The Project Board
-
-GitHub issues are great, but there's no way to easily set priorities.
-To do this, we're using a GitHub Project: https://github.com/exercism/java/projects/2.
-
-- **Epics** — issues that really represent bigger ideas.  These inspire creating a set of smaller issues to be elaborated...
-- **Icebox** — issues that just needs a little more detail to be "ready to play"...
-- **Backlog** — issues ready to be worked.  When we start working on an issue, we move it to the next column...
-- **Current** — issues in progress.  When we've considered it done, we move the card to...
-- **Delivered** — completed issues that could use another pair of eyes.  When these are reviewed they get moved to...
-- **Done** — issues we've complete.  Every so often, we get together and it's nice to review what we've completed. 
-  Once reviewed, we remove them from this Project.
-
-The point of this board is to make clear our shared priorities.  It's a tool you can use.
-However, if you have an idea and want to implement it, you can just do it; it does not have to be added to this board.
-
 ## Miscellaneous
 
 - Issues marked with "policy" are current "team agreements": [exercism?label:policy](https://github.com/search?q=org%3Aexercism+label%3Apolicy).