Update README

1. `unique_digest` is now named `lock_digest`
2. `delete_by_digest` is an instance method

Also fixes the cleanup of digests to use the `delete_by_pattern` method.

README.md

@@ -622,8 +622,8 @@ For sidekiq versions before 5.1 a `sidekiq_retries_exhausted` block is required
 ```ruby
 class MyWorker
   sidekiq_retries_exhausted do |msg, _ex|
-    digest = msg['unique_digest']
-    SidekiqUniqueJobs::Digests.delete_by_digest(digest) if digest
+    digest = msg['lock_digest']
+    SidekiqUniqueJobs::Digests.new.delete_by_digest(digest) if digest
   end
 end
 ```
@@ -633,8 +633,8 @@ Starting in v5.1, Sidekiq can also fire a global callback when a job dies:
 ```ruby
 Sidekiq.configure_server do |config|
   config.death_handlers << ->(job, _ex) do
-    digest = job['unique_digest']
-    SidekiqUniqueJobs::Digests.delete_by_digest(digest) if digest
+    digest = job['lock_digest']
+    SidekiqUniqueJobs::Digests.new.delete_by_digest(digest) if digest
   end
 end
 ```

lib/sidekiq_unique_jobs/testing.rb

@@ -93,7 +93,8 @@ def sidekiq_options(options = {})
       #
       def clear_all
         super
-        SidekiqUniqueJobs::Digests.new.del(pattern: "*", count: 1_000)
+
+        SidekiqUniqueJobs::Digests.new.delete_by_pattern("*", count: 10_000)
       end
     end