chore(ci): test against PHP 7.4

* Updated to test again PHP 7.4 and to use that for coverage reporting.
* Added PHP nightly builds as an allowable failure.
* Added a git ignore as well as a `phpunit` configuration.
* Updated the tests and CI configuration to better handle the juggling of PHP and `phpunit` versions.
* Updated the coveralls dependency to be the latest and greatest instead of the deprecated package.
* Tweaked the README, updated the LICENSE years and bumped this package's version.
* Dropped Patreon link in favor of using Github Sponsors.

phpunit.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit
+  colors="true"
+  convertErrorsToExceptions="true"
+  convertNoticesToExceptions="true"
+  convertWarningsToExceptions="true"
+  failOnRisky="true"
+  stopOnError="true"
+  stopOnFailure="true"
+  stopOnIncomplete="true"
+  verbose="true"
+>
+  <testsuites>
+    <testsuite name="Lorem Ipsum">
+      <directory>tests</directory>
+    </testsuite>
+  </testsuites>
+  <filter>
+    <whitelist addUncoveredFilesFromWhitelist="true">
+      <directory>./src</directory>
+    </whitelist>
+  </filter>
+</phpunit>