chore: Add Scrutinizer configuration.

.scrutinizer.yml

@@ -0,0 +1,21 @@
+build:
+    nodes:
+        analysis:
+            environment:
+                php:
+                    version: 7.4
+            tests:
+                override:
+                    - php-scrutinizer-run
+
+filter:
+    paths:
+        - 'src/*'
+
+tools:
+    external_code_coverage:
+        timeout: 600
+    php_loc: true
+    php_pdepend: true
+    php_sim: true
+    php_changetracking: true