Changed back sprinkle path constant to full app dir path.

Fixes error in CheckEnvironment. Revert part of 
cc736ed. Windows path should be fixed 
from URI package update.

Author: lcharette

app/defines.php

@@ -35,7 +35,7 @@
 define('UserFrosting\SRC_DIR_NAME', 'src');
 
 // Full path to Sprinkles directory
-define('UserFrosting\SPRINKLES_DIR', APP_DIR_NAME . DS . SPRINKLES_DIR_NAME);
+define('UserFrosting\SPRINKLES_DIR', APP_DIR . DS . SPRINKLES_DIR_NAME);
 
 // Full path to sprinkles schema file
 define('UserFrosting\SPRINKLES_SCHEMA_FILE', APP_DIR . DS . 'sprinkles.json');

app/system/Sprinkle/SprinkleManager.php

@@ -34,7 +34,7 @@ class SprinkleManager
     protected $sprinkles = [];
 
     /**
-     * @var string Relaive path to the sprinkles directory. Will be used to register the location with the ResourceLocator
+     * @var string Path to the sprinkles directory. Will be used to register the location with the ResourceLocator
      */
     protected $sprinklesPath = \UserFrosting\SPRINKLES_DIR . \UserFrosting\DS;
 
@@ -60,7 +60,7 @@ public function addResources()
     }
 
     /**
-     * Register a sprinkle as a locator location, using relative path to the sprinkle
+     * Register a sprinkle as a locator location
      * @param string $sprinkleName
      */
     public function addSprinkleResources($sprinkleName)
@@ -85,13 +85,12 @@ public function getSprinklePath($sprinkleName)
         }
 
         // Get path and make sure it exist
-        $relPath = $this->getSprinklesPath() . $sprinkle;
-        $fullpath = \UserFrosting\ROOT_DIR . \UserFrosting\DS . $relPath;
-        if (!file_exists($fullpath)) {
-            throw new FileNotFoundException("Sprinkle `$sprinkleName` should be found at `$fullpath`, but that directory doesn't exist.");
+        $path = $this->getSprinklesPath() . $sprinkle;
+        if (!file_exists($path)) {
+            throw new FileNotFoundException("Sprinkle `$sprinkleName` should be found at `$path`, but that directory doesn't exist.");
         }
 
-        return $relPath;
+        return $path;
     }
 
     /**