add .phpcs.xml enforcing PSR12 and apply fixes

Author: gregor-j

.phpcs.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0"?>
+<ruleset name="PSR12" namespace="GregorJ\Standards">
+    <description>PSR12 programming standard</description>
+    <!-- display progress -->
+    <arg value="p"/>
+    <arg value="n"/>
+    <!-- directories and files to check -->
+    <file>./src</file>
+    <file>./tests</file>
+    <!-- Use PSR12 as a standard -->
+    <rule ref="PSR12">
+    </rule>
+</ruleset>

src/SapDateInterval.php

@@ -1,4 +1,5 @@
 <?php
+
 /**
  * File src/SapDateInterval.php
  *

src/SapDateTime.php

@@ -1,4 +1,5 @@
 <?php
+
 /**
  * File src/SapDateTime.php
  *

tests/SapDateIntervalTest.php

@@ -1,4 +1,5 @@
 <?php
+
 /**
  * File tests/SapDateIntervalTest.php
  *

tests/SapDateTimeTest.php

@@ -1,4 +1,5 @@
 <?php
+
 /**
  * File tests/SapDateTimeTest.php
  *