issue-store.js: Resolve promise directly at first time

[li-boxuan]

This resolves _fetchAllIssues promise directly before polling starts. The benefit is that users don't need to wait until they see pre-fetched cards.

Closes https://github.com/coala/gh-board/issues/173

[li-boxuan]

It has a problem. If the user visits a repo which doesn't have pre-fetched issues, gh-board will remind sth like 'this repo doesn't have issues'.

Also, this strategy wouldn't work if the user redirects to another repo from the dashboard because it uses an instance variable to determine if it is the first fetch. That variable is initialized when the webpage is opened the first time.

[blazeu]

ack c0fa1af1ed152615d7019be30d6e40fb6833ec30

[li-boxuan]

@gitmate-bot rebase

[gitmate-bot]

Hey! I'm GitMate.io! This pull request is being rebased automatically. Please DO NOT push while rebase is in progress or your changes would be lost permanently :warning:

[gitmate-bot]

Automated rebase with GitMate.io was successful! :tada:

[TravisBuddy]

Travis tests have failed

Hey @li-boxuan, Please read the following log in order to understand the failure reason. It'll be awesome if you fix what's wrong and commit the changes.

TravisBuddy Request Identifier: 9b596670-da01-11e8-8964-ad637cdcaaf8

[ashwini0529]

LGTM 💯

[haeungun]

LGTM

[jayvdb]

ack https://github.com/coala/gh-board/pull/174/commits/b81a1b2cb99ac325a1b6c9456f4111607c54af35 https://github.com/coala/gh-board/pull/174/commits/90f7322d06d32e8f3c8771d2544127bab3b4d3bb

[jayvdb]

@gitmate-bot ff

[gitmate-bot]

Hey! I'm GitMate.io! This pull request is being fastforwarded automatically. Please DO NOT push while fastforward is in progress or your changes would be lost permanently :warning:

[gitmate-bot]

Automated fastforward with GitMate.io was successful! :tada: