Fix: Remove invalid configuration from phpunit.xml (#562)

* Enhancement: Reference phpunit.xsd

* Fix: Remove invalid configuration

phpunit.xml.dist

 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
     backupGlobals="false"
     backupStaticAttributes="false"
-    syntaxCheck="false"
     colors="true"
 >
-
     <testsuites>
        <testsuite name="Solarium">
          <directory suffix="Test.php">tests</directory>
@@ -13,11 +13,9 @@
     </testsuites>
 
     <logging>
-      <log type="coverage-html" target="build/coverage" title="Solarium"
-       charset="UTF-8" yui="true" highlight="true"
-       lowUpperBound="35" highLowerBound="70"/>
+      <log type="coverage-html" target="build/coverage" lowUpperBound="35" highLowerBound="70"/>
       <log type="coverage-clover" target="build/logs/clover.xml"/>
-      <log type="junit" target="build/logs/junit.xml" logIncompleteSkipped="false"/>
+      <log type="junit" target="build/logs/junit.xml"/>
     </logging>
 
     <filter>

phpunit.xml.travis

 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
     backupGlobals="false"
     backupStaticAttributes="false"
-    syntaxCheck="false"
+    colors="true"
 >
     <testsuites>
        <testsuite name="Solarium">