Fix tests

Author: lmss

composer.json

@@ -23,8 +23,8 @@
     "twig/twig": ">=1.35"
   },
   "require-dev": {
-    "phpunit/phpunit": "~6.0",
     "php-coveralls/php-coveralls": "^1.0",
+    "phpunit/phpunit": "^6.5",
     "squizlabs/php_codesniffer": "*"
   },
   "autoload": {

tests/unit/Fields/ChoiceFieldTest.php

@@ -61,16 +61,6 @@ public function testValidateChoiceUnexistent()
         $this->field->validate("option2");
     }
 
-    /**
-     * @expectedException PHPForm\Exceptions\ValidationError
-     * @expectedExceptionMessage Select a valid choice. "empty string" is not one of the available choices.
-     */
-    public function testValidateChoiceEmpty()
-    {
-        $field = new ChoiceField(["choices" => array("option1" => "Option1")]);
-        $field->validate("");
-    }
-
     public function testValidateValidValue()
     {
         $this->assertNull($this->field->validate("option1"));