Laravel 5.6 updates

Travis config update

Removed HHVM script as Laravel no longer support HHVM after releasing 5.3

vendor/phar-io/version/src/exceptions/Exception.php

@@ -0,0 +1,14 @@
+<?php
+/*
+ * This file is part of PharIo\Version.
+ *
+ * (c) Arne Blankerts <arne@blankerts.de>, Sebastian Heuer <sebastian@phpeople.de>, Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace PharIo\Version;
+
+interface Exception {
+}

vendor/phar-io/version/src/exceptions/InvalidPreReleaseSuffixException.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace PharIo\Version;
+
+class InvalidPreReleaseSuffixException extends \Exception implements Exception {
+
+}

vendor/phar-io/version/src/exceptions/InvalidVersionException.php

@@ -0,0 +1,6 @@
+<?php
+
+namespace PharIo\Version;
+
+class InvalidVersionException extends \InvalidArgumentException implements Exception {
+}

vendor/phar-io/version/src/exceptions/UnsupportedVersionConstraintException.php

@@ -0,0 +1,14 @@
+<?php
+/*
+ * This file is part of PharIo\Version.
+ *
+ * (c) Arne Blankerts <arne@blankerts.de>, Sebastian Heuer <sebastian@phpeople.de>, Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace PharIo\Version;
+
+final class UnsupportedVersionConstraintException extends \RuntimeException implements Exception {
+}