v6.0.0

Changed

• Increased the minimum required PHP version to 7.1

Breaking changes

• Added the appropriate type hints to publicly available methods:

   // Cache:
   abstract protected function get(string $key); -> abstract protected function get(string $key): ?string;
   abstract protected function get(string $key); -> abstract protected function set(string $key, string $value): void;
     
   // ConfigCatClient:
   function getValue($key, $defaultValue, User $user = null) -> function getValue(string $key, $defaultValue, User $user = null)
   function getVariationId($key, $defaultVariationId, User $user = null) -> function getVariationId(string $key, $defaultVariationId, User $user = null)
   function getAllVariationIds(User $user = null) -> function getAllVariationIds(User $user = null): array
   function getKeyAndValue($variationId) -> function getKeyAndValue(string $variationId): ?Pair
   function getAllKeys() -> function getAllKeys(): array
   function getAllValues(User $user = null) -> function getAllValues(User $user = null): array
   function forceRefresh() -> function forceRefresh(): void