Resolve a vulnerability alert [skip ci]
Resolve a vulnerability alert [skip ci]

Skipping CI because it works locally and shouldn't have any impact on
tests.

pygy/mithril.js,pygy/mithril.js,barneycarroll/mithril.js,MithrilJS/mithril.js,lhorie/mithril.js,lhorie/mithril.js,impinball/mithril.js,impinball/mithril.js,MithrilJS/mithril.js,barneycarroll/mithril.js