Fix focused JS tests fail due to implicit npm dependency

[viddo]

Fixes #5147

Bumping up to latest versions for outdated packages makes things works 🎉 (this was needed sooner or later anyways)
…except for gulp-* modules, because at least one native binding (gulp-ttf2woff2 doesn't seem to be used in currently specified versions) requires a newer version of node (v0.12). I don't want to force an upgrade to break builds or other dependencies that requires this older versions. We can investigate and bump those in isolation.

There's a little caveat of bumping the versions; I documented it inline with the code change edit: v3.4.2 of buffer module was released, so no temporary workaround needed anymore.

Also set all dependencies to use specific versions, to avoid dependency versions mismatches (per recommendation by @rochoa).

Verifying that things work (on my machine™):

• Testing the typical builds (both local and production)
• Running all tests locally (both headless and in browser)
• Provoke a failing test un purpose (see screenshot below)
• Browsing locally
• Review build output

forced failed test, with proper stack trace

@xavijam since you suffered the focused-tests issues originally
@CartoDB/frontend FYI

[viddo]

Bump @xavijam can you verify that this fixes your trouble?

[xavijam]

Yay! confirmed! 🇪🇸