Update test instructions to support PHPUnit 6 and PHPUnit 5

Author: clue

.travis.yml

@@ -14,4 +14,4 @@ install:
   - composer install --no-interaction
 
 script:
-  - php vendor/bin/phpunit --coverage-text
+  - vendor/bin/phpunit --coverage-text

README.md

@@ -102,10 +102,14 @@ A list of all official components can be found in the [graphp project](https://g
 ## Tests
 
 This library uses PHPUnit for its extensive test suite.
-You can either use a global installation or rely on the one composer installs
-when you first run `$ composer install`.
-This sets up the developer environment, so that you
-can now run it from the project root directory:
+To run the test suite, you first need to clone this repo and then install all
+dependencies [through Composer](https://getcomposer.org):
+
+```bash
+$ composer install
+```
+
+To run the test suite, go to the project root and run:
 
 ```bash
 $ php vendor/bin/phpunit

_config.yml

@@ -25,7 +25,7 @@
         "php": "^7.0 || ^5.3"
     },
     "require-dev": {
-        "phpunit/phpunit": "~4.0"
+        "phpunit/phpunit": "^6.4 || ^5.7 || ^4.8.35"
     },
     "suggest": {
         "graphp/graphviz": "GraphViz graph drawing / DOT output",

composer.json

@@ -203,15 +203,15 @@ public function testCreateVerticesNone()
     /**
      * expect to fail for invalid number of vertices
      * @expectedException InvalidArgumentException
-     * @dataProvider testCreateVerticesFailProvider
+     * @dataProvider createVerticesFailProvider
      */
     public function testCreateVerticesFail($number)
     {
         $graph = new Graph();
         $graph->createVertices($number);
     }
 
-    public static function testCreateVerticesFailProvider()
+    public static function createVerticesFailProvider()
     {
         return array(
             array(-1),

tests/GraphTest.php

@@ -6,10 +6,9 @@
 use Fhaculty\Graph\Edge\Base as Edge;
 use Fhaculty\Graph\Graph;
 use Fhaculty\Graph\Vertex;
-use Fhaculty\Graph\Set\Vertices;
-use PHPUnit_Framework_TestCase;
+use PHPUnit\Framework\TestCase as BaseTestCase;
 
-class TestCase extends PHPUnit_Framework_TestCase
+class TestCase extends BaseTestCase
 {
     protected function assertGraphEquals(Graph $expected, Graph $actual)
     {
@@ -29,11 +28,8 @@ protected function assertGraphEquals(Graph $expected, Graph $actual)
         // do not use assertVertexEquals() in order to not increase assertion counter
 
         foreach ($expected->getVertices()->getMap() as $vid => $vertex) {
-            try {
-                $other = $actual->getVertex($vid);
-            } catch (Exception $e) {
-                $this->fail();
-            }
+            $other = $actual->getVertex($vid);
+
             if ($this->getVertexDump($vertex) !== $this->getVertexDump($vertex)) {
                 $this->fail();
             }