Can't find package manager files (package.json, etc.) when using --directory

[quinnturner]

Steps for reproduction:

audit-ci -l --directory ./test/yarn-high/

Result:

Invocation of npm audit failed:
npm ERR! code EAUDITNOLOCK
npm ERR! audit Neither npm-shrinkwrap.json nor package-lock.json found: Cannot audit a project without a lockfile
npm ERR! audit Try creating one first with: npm i --package-lock-only
npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\Quinn Turner\AppData\Roaming\npm-cache\_logs\2019-02-27T00_41_24_516Z-debug.log
Exiting...

Expected:
Valid audit