Move common app data directory method to UnixSystem

Author: bstoney

src/System/BsdSystem.php

@@ -11,10 +11,4 @@ public function getOperativeSystem()
     {
         return self::OS_BSD;
     }
-
-    /** @return string */
-    public function getAppDataDirectory()
-    {
-        return $this->getCurrentUserHome().'/.jupyter-php';
-    }
 }

src/System/LinuxSystem.php

@@ -11,10 +11,4 @@ public function getOperativeSystem()
     {
         return self::OS_LINUX;
     }
-
-    /** @return string */
-    public function getAppDataDirectory()
-    {
-        return $this->getCurrentUserHome().'/.jupyter-php';
-    }
 }

src/System/UnixSystem.php

@@ -50,6 +50,12 @@ public function checkIfCommandExists($cmdName)
         return filter_var($sysResponse, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
     }
 
+    /** @return string */
+    public function getAppDataDirectory()
+    {
+        return $this->getCurrentUserHome().'/.jupyter-php';
+    }
+
     /**
      * Returns true if the path is a "valid" path and is writable (even if the complete path does not yet exist).
      * @param string $path