Add GitHub Enterprise support to github-issues

src/scripts/github-issues.coffee

@@ -11,6 +11,7 @@
 #   HUBOT_GITHUB_USER
 #   HUBOT_GITHUB_REPO
 #   HUBOT_GITHUB_USER_(.*)
+#   HUBOT_GITHUB_API
 #
 # Commands:
 #   hubot show [me] [<limit> [of]] [<assignee>'s|my] [<label>] issues [for <user/repo>] [about <query>] -- Shows open GitHub issues for repo.
@@ -24,6 +25,8 @@
 #   'johndoe1', you can ask `show john's issues` instead of `show johndoe1's
 #   issues`. This is useful for mapping chat handles to GitHub logins.
 #
+#   HUBOT_GITHUB_API allows you to set a custom URL path (for Github enterprise users)
+#
 # Author:
 #   davidsiegel
 
@@ -81,7 +84,8 @@ module.exports = (robot) ->
     query_params.labels = criteria.label if criteria.label?
     query_params.assignee = criteria.assignee if criteria.assignee?
 
-    github.get "https://api.github.com/repos/#{criteria.repo}/issues", query_params, (issues) ->
+    base_url = process.env.HUBOT_GITHUB_API || 'https://api.github.com'
+    github.get "#{base_url}/repos/#{criteria.repo}/issues", query_params, (issues) ->
       issues = filter_issues issues, criteria
 
       if _.isEmpty issues