Added snyk.io badge.
Added snyk.io badge.

Brantone/node-build-monitor,HelloHolyLi/node-build-monitor,Brantone/node-build-monitor,HelloHolyLi/node-build-monitor,marcells/node-build-monitor,marcells/node-build-monitor,Brantone/node-build-monitor,HelloHolyLi/node-build-monitor