Do not return updateComplete at the end of requestUpdate

[Christian24]

This addresses an issue mentioned in #469. When implementing custom accessors, TS-Lint always has a finding on calling requestUpdate, because the result of the returned promise is ignored. As async and await is not supported in accessors anyway, my suggestion is to just not return updateComplete, as the return value is never used in the source code anyway and can easily be substituted for updateComplete get accessor if needed.

[googlebot]

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[Christian24]

I need to work some more on this, before it is ready. Sorry, for the fast first shot.

[Christian24]

I guess the CLA check failed, because I have used to a different email address in my first commit.

[daKmoR]

for the cla I think you should just erase your history and make a new commit and then force push

e.g. something like this

git reset --soft <hashOfLastCommitThatIsNotYours>
git commit ...
git push --force

[Christian24]

Since @justinfagnani made clear in #469 this won't be merged, because of the API change, I will close this now. Would love to have an option like requestUpdateSync in the future though.