Create spec file for Parser

spec/imbecile/regex/parser_spec.rb

@@ -0,0 +1,11 @@
+module Imbecile
+  class Regex
+    RSpec.describe Parser do
+
+      it "parses various expressions" do
+        expect(Parser.new("").unit).to be_a Parser::AlternatesUnit
+      end
+
+    end
+  end
+end