add psalm and travis check

More/EAV/Entity.php

@@ -2,10 +2,12 @@
 
 namespace DesignPatterns\More\EAV;
 
+use SplObjectStorage;
+
 class Entity
 {
     /**
-     * @var \SplObjectStorage
+     * @var SplObjectStorage<Value,Value>
      */
     private $values;
 
@@ -20,7 +22,7 @@ class Entity
      */
     public function __construct(string $name, $values)
     {
-        $this->values = new \SplObjectStorage();
+        $this->values = new SplObjectStorage();
         $this->name = $name;
 
         foreach ($values as $value) {

More/EAV/Value.php

@@ -24,6 +24,6 @@ class Value
 
     public function __toString(): string
     {
-        return sprintf('%s: %s', $this->attribute, $this->name);
+        return sprintf('%s: %s', (string) $this->attribute, $this->name);
     }
 }

More/ServiceLocator/ServiceLocator.php

@@ -5,18 +5,17 @@ namespace DesignPatterns\More\ServiceLocator;
 class ServiceLocator
 {
     /**
-     * @var array|Service[]
+     * @var string[][]
      */
     private $services = [];
 
     /**
-     * @var array|Service[]
+     * @var Service[]
      */
     private $instantiated = [];
 
     public function addInstance(string $class, Service $service)
     {
-        $this->services[$class] = $service;
         $this->instantiated[$class] = $service;
     }
 
@@ -55,6 +54,10 @@ class ServiceLocator
                 throw new \OutOfRangeException('Too many arguments given');
         }
 
+        if (!$object instanceof Service) {
+            throw new \InvalidArgumentException('Could not register service: is no instance of Service');
+        }
+
         $this->instantiated[$class] = $object;
 
         return $object;