prebuilt: add electron 6.0.0

[pdesantis]

This adds support for Electron 6.0.0. I used the same technique as #1160 and #1180.

Electron 6.0.0 was released on 7/30/2019.
https://electronjs.org/releases/stable#release-notes-for-v600

[pdesantis]

I filed a separate issue (#1197) for the failing Travis job, as it seems to be a preexisting issue that isn't caused by these changes.

[pdesantis]

Thanks for fixing the tests @kewde !

[pdesantis]

@kewde (or anyone else) - is there anything else needed from me before this can be merged?

[nicolasgere]

Are there any plans on doing a release with this soon? Electron 6 support would be great for my project. Thanks

[sulf]

+1 @kewde would be great to have this merged!

[mapsam]

👍 thanks all - merging this in, and will publish as 4.0.10

@kewde noticing some missing changelog updates for 4.0.8 and 4.0.9 - any chance you could follow up with an update there? Thanks!

[mapsam]

FYI - this will go out in 4.1.0, not 4.0.10, as there are some other changes in master that warrant a minor!

[mapsam]

[email protected] published with all binaries built! https://travis-ci.org/mapbox/node-sqlite3/builds/572804185

[pdesantis]

Awesome, thanks all!