[PHP] fix PHPUnit invocation, add basic phpunit.xml.dist (#3864)

* feature(phpunit) fix PHPUnit invocation, add basic phpunit.xml.dist

* fix(phpunit) add proper paths relative to phpunit.xml.dist

modules/swagger-codegen/src/main/resources/php/.travis.yml

@@ -7,4 +7,4 @@ php:
     - 7.0
     - hhvm
 before_install: "composer install"
-script: "phpunit lib/Tests"
+script: "vendor/bin/phpunit"

modules/swagger-codegen/src/main/resources/php/README.mustache

@@ -56,7 +56,7 @@ To run the unit tests:
 
 ```
 composer install
-./vendor/bin/phpunit lib/Tests
+./vendor/bin/phpunit
 ```
 
 ## Getting Started

modules/swagger-codegen/src/main/resources/php/phpunit.xml.mustache

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit bootstrap="./vendor/autoload.php"
+         colors="true"
+         convertErrorsToExceptions="true"
+         convertNoticesToExceptions="true"
+         convertWarningsToExceptions="true"
+         stopOnFailure="false">
+    <testsuites>
+        <testsuite>
+            <directory>{{apiTestPath}}</directory>
+            <directory>{{modelTestPath}}</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">{{apiSrcPath}}</directory>
+            <directory suffix=".php">{{modelSrcPath}}</directory>
+        </whitelist>
+    </filter>
+</phpunit>