DepsDevAPIClient is a wrapper for InsightsClient that caches requests.

RequestCache is a map to cache the results of expensive functions that are called concurrently.

Implementation of npm registry auth matching, adapted from npm-registry-fetch https://github.com/npm/npm-registry-fetch/blob/237d33b45396caa00add61e0549cf09fbf9deb4f/lib/auth.js.