Correct copyright's term of CoderDojo Japan

Author: yasulab

README.md

@@ -53,7 +53,7 @@ So, this application can be used and modified under the MIT License! 🆗
 
 ### The MIT License (MIT)
 
-Copyright © 2017 [CoderDojo Japan](https://coderdojo.jp/)
+Copyright © 2012-2017 [CoderDojo Japan](https://coderdojo.jp/)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

app/views/shared/_footer.html.erb

@@ -1,4 +1,4 @@
 <footer class="text-right">
   <p class="text-muted" style="font-size:80%;">Developed and designed by <a href="http://yasslab.jp/">YassLab</a>.<br />
-  Copyright © 2016 <a href="/">CoderDojo Japan</a>.</p>
+  Copyright © 2012-2017 <a href="/">CoderDojo Japan</a>.</p>
 </footer>

app/views/shared/_footer_page.html.erb

@@ -5,5 +5,5 @@
     | <a href="/sotechsha" class="footer-link">公式ブック</a>
   </h2>
   <p>本サイトのソースコードや社団法人の定款などは <a href="https://github.com/coderdojo-japan/" class="footer-link">GitHub</a> 上で公開されています。</p>
-  <p>Copyright © 2016 一般社団法人 CoderDojo Japan</p>
+  <p>Copyright © 2012-2017 一般社団法人 CoderDojo Japan</p>
 </footer>