add phpcs & phpunit config

Author: LKaemmerling

phpcs.xml.dist

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<ruleset name="PHP_CodeSniffer">
+    <file>src/</file>
+    <file>tests/</file>
+    <file>examples/</file>
+
+    <exclude-pattern type="relative">vendor/*</exclude-pattern>
+
+    <arg value="nps"/>
+
+    <rule ref="PSR12"/>
+</ruleset>

phpunit.xml.dist

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit backupGlobals="false"
+         backupStaticAttributes="false"
+         bootstrap="tests/bootstrap.php"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         processIsolation="false"
+         stopOnError="false"
+         stopOnFailure="false">
+
+    <testsuites>
+        <testsuite name="Unit">
+            <directory>./tests/Test/PrometheusPushGateway</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">./src/PrometheusPushGateway</directory>
+        </whitelist>
+    </filter>
+</phpunit>