flippy 8.x-1.0-beta1

Issue #2806589: Sort by other fields: Support Node title
Issue #2875327: When only one node exists, flippy throws a notice on 'first' and 'last' index
Issue #2880341: Convert module to use short array syntax (new coding standard).
Issue #2743443: Filter list results
Issue #2824069: Undefined index: in template_preprocess_flippy()
Issue #2802877: "The requested page could not be found" after clic on flippy buttons
Issue #2801803: Adjust condition for prev/next availability
Issue #2801805: Provide some kind of identification for empty prev/next links
Issue #2801801: Stop removing node object in preprocess function
Issue #2795807: Add hook suggestion on flippy theme
Issue #1785722: on key press navigate to the next node
Issue #2792735: Dependency injection in block plugin
Issue #2793877: Undefined offset notices in FlippyPager
Issue #2790537: Inject database connection query factory and config into the FlippyPager service.
Issue #2784207: Support translation of labels
Issue #2784731: Add support for datetime field sorting
Issue #2789799: Convert selectQuery to entityQuery
Issue #2785171: Adding caching metadata to block
Issue #2769769: Render links in twig to make themeing easier
Issue #2756749: Drupal\Component\Serialization\Exception\InvalidDataTypeException: The reserved indicator "@" cannot start a plain scalar; you need to quote the scalar
Issue #2752957: Fix block
Issue #2468393: Flippy chorus slightly off key
Issue #2678228: Prev/Next head links generate a fatal error
Issue #2700769: Strict warning: Only variables should be passed by reference in template_preprocess_flippy()
Issue #2547677: Css path is wrong
Issue #2667664: Warning: Missing argument 5 for flippy_node_view() in flippy_node_view() (line 341 of modules/flippy/flippy.module).
Issue #2501709: Streamline use of \Drupal::config('flippy.settings')