Add in composer reqs for Laravel v9 (mikefrancis#43) 

Fix isFeatureEnabled returns false when multiple strategies are confi… …gured (mikefrancis#33)

UserWithId Strategy calls id() method on User Model (mikefrancis#32) 

Make endpoint and request options configurable. (mikefrancis#28) 

Add Middleware feature.enabled, feature.disabled (mikefrancis#26) 

Bind GuzzleHttpClient as default client for Unleash. (mikefrancis#29) 

Add support for failover cache (mikefrancis#23) - Changes cache TTL default to 15s, the standard default - Add unleash.cache.failover option that will pull the last successful result from the cache - This setting is independent of regular caching - The cache is always stored, to allow enabling the feature during a failure incidence - This change also moves the requests for features out of the constructor - Possible to use in Facades - Still "cached" for the lifetime of the Unleash object

Allow passing variadic args into `Unleash->isFeatureEnabled()`/`Unlea… …sh->isFeatureDisabled()` (mikefrancis#22) This change allows for more complex strategies to be employed that rely on runtime data not available in the request.

Add Unleash and Feature facades (mikefrancis#24) 

Update composer.json (mikefrancis#15)