Enable some eslint rules again and update the code to follow them

[maxceem]

During updating eslint to 6.8.0 version I had to disable some rules to avoid multiple changes across the codebase, as we have branch feature/bulk-milestone-updates with quite wast changes, to avoid merge conflicts later.

After we merge feature/bulk-milestone-updates to develop we should re-enable the eslint rules disable in this PR https://github.com/topcoder-platform/tc-project-service/pull/537/files#diff-1dc6ee56b778cd91e0327b52aaeaa1b9 and fix the source code accordingly.

[maxceem]

@vikasrohit this is done via PR #566.

Before merging it, I would like to confirm, that there is no one working on a big change in Project Service. Because this PR contains a lot of trivial fixes to formatting which might cause merge conflicts to any big PR.

Note: existent big PR #540 would be updated, so this one is under control.

[vikasrohit]

Yep, we don't have any other major feature as of now in progress.

[vikasrohit]

@maxceem should we merge #566 before #540?

[maxceem]

@maxceem should we merge #566 before #540?

Yes, #540 is waiting for client-side changes so we cannot merge it yet. I would keep it in sync with develop branch.