Fix typo in spec

Author: sferik

spec/parser/option_spec.rb

@@ -176,7 +176,7 @@ def option(name, options={})
     end
 
     it "uses padding when no aliases are given" do
-      expect(parse(:foo, :boolean).usage)).to eq("    [--foo]")
+      expect(parse(:foo, :boolean).usage).to eq("    [--foo]")
     end
 
     it "uses banner when supplied" do