[#177] Added fetch functionality

[dylanfu]

Resolves #177 and Resolves #258 .

Fetches from all the remotes. Can't fetch from a single remote due to deadlock issues. Added new logos for remote and fetch.

To test:

1. Login.
2. Open a repository
3. Press the fetch button in navbar

• Also make sure npm t works

Expected behaviour:

• Popup message confirming fetch was successful
• Popup message saying it failed if remotes have incorrect urls

NOTE:

• If testing using VisualGit repo, make sure to remove " mocks " when testing as it causes errors with fetch and pull. I have moved mocks in my PR.

[dylanfu]

@Emap900 I encounter this with pull as well. Seems to be something wrong with fetching multiple remotes. Trying to fix it.

[hybrio]

is it possible that it's based on the save location/filename of the remotes? (because they all save in a folder named VisualGit_SE701_2019_4)

[dylanfu]

@Emap900 @qhen143 @hybrio I fixed it, had to move mocks out of the root directory. Could you please test it now?

[dylanfu]

@qhen143 This PR is for mainly for fetch functionality. The tooltip error is a separate issue.