Namespaces on own line (roots#1712)

`namespace` declarations appear on their own line in PHP FIG examples as well as in common PHP frameworks. While not officially part of PSR-2, we should still follow this common practice of not putting `namespace` declaration on the same line as `<?php`.

- http://www.php-fig.org/psr/psr-2/
- https://github.com/laravel/laravel/blob/master/app/User.php#L1-L3
- https://github.com/symfony/filesystem/blob/master/Filesystem.php#L1-L12
- https://github.com/zendframework/zend-mail/blob/master/src/Address.php#L1-L10

src/admin.php

@@ -1,4 +1,6 @@
-<?php namespace App;
+<?php
+
+namespace App;
 
 /**
  * Theme customizer

src/filters.php

@@ -1,4 +1,6 @@
-<?php namespace App;
+<?php
+
+namespace App;
 
 use Roots\Sage\Template;
 use Roots\Sage\Template\Wrapper;

src/helpers.php

@@ -1,4 +1,6 @@
-<?php namespace App;
+<?php
+
+namespace App;
 
 use Roots\Sage\Asset;
 use Roots\Sage\Assets\JsonManifest;

src/lib/Sage/Asset.php

@@ -1,4 +1,6 @@
-<?php namespace Roots\Sage;
+<?php
+
+namespace Roots\Sage;
 
 use Roots\Sage\Assets\ManifestInterface;
 

src/lib/Sage/Assets/JsonManifest.php

@@ -1,4 +1,6 @@
-<?php namespace Roots\Sage\Assets;
+<?php
+
+namespace Roots\Sage\Assets;
 
 /**
  * Class JsonManifest

src/lib/Sage/Assets/ManifestInterface.php

@@ -1,4 +1,6 @@
-<?php namespace Roots\Sage\Assets;
+<?php
+
+namespace Roots\Sage\Assets;
 
 /**
  * Interface ManifestInterface

src/lib/Sage/Template.php

@@ -1,4 +1,6 @@
-<?php namespace Roots\Sage;
+<?php
+
+namespace Roots\Sage;
 
 use Roots\Sage\Template\Partial;
 use Roots\Sage\Template\WrapperInterface;

src/lib/Sage/Template/Partial.php

@@ -1,4 +1,6 @@
-<?php namespace Roots\Sage\Template;
+<?php
+
+namespace Roots\Sage\Template;
 
 class Partial
 {

src/lib/Sage/Template/Wrapper.php

@@ -1,4 +1,6 @@
-<?php namespace Roots\Sage\Template;
+<?php
+
+namespace Roots\Sage\Template;
 
 /**
  * Class Wrapper

src/lib/Sage/Template/WrapperInterface.php

@@ -1,4 +1,6 @@
-<?php namespace Roots\Sage\Template;
+<?php
+
+namespace Roots\Sage\Template;
 
 /**
  * Interface WrapperInterface

src/setup.php

@@ -1,4 +1,6 @@
-<?php namespace App;
+<?php
+
+namespace App;
 
 use Roots\Sage\Template;