Crashes when hit enter on empty Channels tab

[TintypeMolly]

How to reproduce

1. Run slack-tui
2. hit tab to select Channels tab
3. hit enter

Result

It crashes

Error Log

➜  ~ slack-tui
TypeError: Cannot read property 'selectChannel' of null
    at List.<anonymous> (/home/tintypemolly/workspace/slack-tui/index.js:391:35)
    at List.EventEmitter._emit (/home/tintypemolly/workspace/slack-tui/node_modules/blessed/lib/events.js:94:20)
    at List.EventEmitter.emit (/home/tintypemolly/workspace/slack-tui/node_modules/blessed/lib/events.js:117:12)
    at List.enterSelected (/home/tintypemolly/workspace/slack-tui/node_modules/blessed/lib/widgets/list.js:586:8)
    at List.<anonymous> (/home/tintypemolly/workspace/slack-tui/node_modules/blessed/lib/widgets/list.js:119:14)
    at List.EventEmitter._emit (/home/tintypemolly/workspace/slack-tui/node_modules/blessed/lib/events.js:94:20)
    at List.EventEmitter.emit (/home/tintypemolly/workspace/slack-tui/node_modules/blessed/lib/events.js:117:12)
    at Program.<anonymous> (/home/tintypemolly/workspace/slack-tui/node_modules/blessed/lib/widgets/screen.js:602:15)
    at emitTwo (events.js:126:13)
    at Program.emit (events.js:214:7)