fixup: Extract driver to const.
fixup: Extract driver to const.

Consistancy fixup.

wardpeet/lighthouse,cedricbellet/lighthouse,mixed/lighthouse,GoogleChrome/lighthouse,tkadlec/lighthouse,deepanjanroy/lighthouse,cedricbellet/lighthouse,cedricbellet/lighthouse,GoogleChrome/lighthouse,GoogleChrome/lighthouse,ev1stensberg/lighthouse,wardpeet/lighthouse,deepanjanroy/lighthouse,wardpeet/lighthouse,tkadlec/lighthouse,tommycli/lighthouse,deepanjanroy/lighthouse,umaar/lighthouse,arturmiz/lighthouse,ev1stensberg/lighthouse,ev1stensberg/lighthouse,zhaoz/lighthouse,arturmiz/lighthouse,umaar/lighthouse,tommycli/lighthouse,tommycli/lighthouse,tommycli/lighthouse,arturmiz/lighthouse,mixed/lighthouse,umaar/lighthouse,GoogleChrome/lighthouse,cedricbellet/lighthouse,tkadlec/lighthouse,ev1stensberg/lighthouse,deepanjanroy/lighthouse,zhaoz/lighthouse,deepanjanroy/lighthouse,tkadlec/lighthouse,mixed/lighthouse,wardpeet/lighthouse,arturmiz/lighthouse,umaar/lighthouse,wardpeet/lighthouse,tommycli/lighthouse,zhaoz/lighthouse,arturmiz/lighthouse,mixed/lighthouse,GoogleChrome/lighthouse,cedricbellet/lighthouse