Use files instead of package-file without php-mode.el

It is not necessary to specify in package-file except the main file of the package.

Author: zonuexe

Cask

@@ -1,11 +1,13 @@
 (package "php-mode" "1.23.0" "Major mode for editing PHP code")
 (source melpa)
 
-(package-file "php.el")
-(package-file "php-face.el")
 (package-file "php-mode.el")
-(package-file "php-project.el")
-(package-file "php-mode-debug.el")
+
+(files
+ "php.el"
+ "php-face.el"
+ "php-project.el"
+ "php-mode-debug.el")
 
 (development
  (depends-on "pkg-info")