Add https proxy support

Author: mtchurch

package.json

@@ -22,7 +22,7 @@
     "url": "https://github.com/slackhq/hubot-slack/issues"
   },
   "dependencies": {
-    "slack-client": "~1.4.0"
+    "slack-client": "~1.5"
   },
   "devDependencies": {
     "coffee-script": "~1.7.1",

src/slack.coffee

@@ -22,14 +22,15 @@ class SlackBot extends Adapter
       autoReconnect: !exitProcessOnDisconnect
       autoMark: true
       exitOnDisconnect: exitProcessOnDisconnect
+      proxyUrl: process.env.https_proxy
 
     return @robot.logger.error "No services token provided to Hubot" unless options.token
     return @robot.logger.error "v2 services token provided, please follow the upgrade instructions" unless (options.token.substring(0, 5) in ['xoxb-', 'xoxp-'])
 
     @options = options
 
     # Create our slack client object
-    @client = new SlackClient options.token, options.autoReconnect, options.autoMark
+    @client = new SlackClient options.token, options.autoReconnect, options.autoMark, options.proxyUrl
 
     # Setup event handlers
     # TODO: Handle eventual events at (re-)connection time for unreads and provide a config for whether we want to process them