do some trivial codestyle fixes

unix newlines, trailing spaces

lib/MrClay/Cli/Arg.php

@@ -97,6 +97,7 @@ class Arg {
     public function useAsOutfile()
     {
         $this->spec['useAsOutfile'] = true;
+
         return $this->assertFile()->assertWritable();
     }
 
@@ -109,6 +110,7 @@ class Arg {
     public function useAsInfile()
     {
         $this->spec['useAsInfile'] = true;
+
         return $this->assertFile()->assertReadable();
     }
 
@@ -127,6 +129,7 @@ class Arg {
     public function setDescription($desc)
     {
         $this->description = $desc;
+
         return $this;
     }
 
@@ -164,6 +167,7 @@ class Arg {
         } else {
             throw new BadMethodCallException('Method does not exist');
         }
+
         return $this;
     }
 
@@ -178,6 +182,7 @@ class Arg {
         if (array_key_exists($name, $this->spec)) {
             return $this->spec[$name];
         }
+
         return null;
     }
 }