refactor: use load-json-file in install/isAvailable
refactor: use load-json-file in install/isAvailable

rstacruz/pnpm,pnpm/pnpm,rstacruz/pnpm,pnpm/supi,rstacruz/pnpm,andreypopp/pnpm,andreypopp/pnpm,pnpm/supi,pnpm/pnpm,pnpm/supi,andreypopp/pnpm,pnpm/pnpm