Allow calling `Options#separator` without args, defaulting to an empty string

It's clear that we want an empty line when calling `opts.separator`
without arguments.

Leave the examples in the Readme still for a while with the empty string
to avoid confusion when using older versions.

1 files changed, 6 insertions, 0 deletions

diff --git a/test/options_test.rb b/test/options_test.rb
index 3ef34c5..f816b74 100644
--- a/test/options_test.rb
+++ b/test/options_test.rb
@@ -64,6 +64,12 @@ describe Slop::Options do
       @options.separator("foo".freeze)
       @options.separator("bar".freeze)
     end
+
+    it "defaults to empty string" do
+      @options.separator
+
+      assert_equal [""], @options.separators
+    end
   end
 
   describe "#method_missing" do