fix lib file for rubocop

jekyll-transistor.gemspec

@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name        = 'jekyll-transistor'
-  s.version     = '0.0.3'
+  s.version     = '0.0.4'
   s.date        = '2020-05-04'
   s.summary     = "A transistor.fm plugin liquid tag for Jekyll"
   s.description = "Allows to embed Transistor.fm audio bits in Jekyll pages and posts."

lib/jekyll-transistor.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 #  Transistor embed tag for Jekyll/Liquid
 #
 #  Usage:
@@ -16,22 +18,22 @@
 require 'shellwords'
 
 module Jekyll
+  # Transistor sound tag for Jekyll
   class TransistorSoundTag < Liquid::Tag
-
     def initialize(tag_name, markup, tokens)
       super
       params = Shellwords.shellwords markup
-      @sound = { :id => params[0], :color => params[1] || "light" }
+      @sound = { id: params[0], color: params[1] || 'light' }
     end
 
-    def render(context)
+    def render(_context)
       url = "https://share.transistor.fm/e/#{@sound[:id]}"
-      url += "/dark" if @sound[:color] == 'dark'
-      "<iframe src='#{url}' width='100%' height='180' frameborder='0' scrolling='no' seamless='true' style='width:100%; height:180px;'></iframe>"
+      url += '/dark' if @sound[:color] == 'dark'
+      "<iframe src='#{url}' width='100%' height='180' frameborder='0' "\
+      "scrolling='no' seamless='true' style='width:100%; height:180px;'>"\
+      '</iframe>'
     end
-
   end
-
 end
 
 Liquid::Template.register_tag('transistor_sound', Jekyll::TransistorSoundTag)