Add persister by default to avoid having persist(required: true) but no persister

[lucas34]

This is a Breaking Changes

[lucas-bot]

SwiftLint found issues

Warnings

File	Line	Reason
SqOperationQueue.swift	17	Line should be 140 characters or less: currently 148 characters
SwiftQueueManager.swift	24	Line should be 140 characters or less: currently 159 characters
SwiftQueueTests.swift	143	Limit vertical whitespace to a single empty line. Currently 2.

Generated by 🚫 Danger

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@655776b). Click here to learn what that means.
The diff coverage is 93.75%.

@@            Coverage Diff            @@
##             master     #119   +/-   ##
=========================================
  Coverage          ?   99.07%           
=========================================
  Files             ?       22           
  Lines             ?     1625           
  Branches          ?        0           
=========================================
  Hits              ?     1610           
  Misses            ?       15           
  Partials          ?        0

Impacted Files	Coverage Δ
Tests/SwiftQueueTests/SwiftQueueTests.swift	100% <100%> (ø)
Sources/SwiftQueue/SqOperationQueue.swift	98.48% <100%> (ø)
Sources/SwiftQueue/SwiftQueueManager.swift	97.36% <83.33%> (ø)