Remove code snippet collapse

[Atlas7]

The fix is related to this issue - Markdown code snippet "disappear" (collapse) unexpectedly upon clicking

What this commit does:

• now that the code snippet collapse bug is commented out in main javascript, as per this previous commit, we still need to remove the corresponding part in the minified javascript blog-20171204.min.js. This commit does just that to ensure the fix is properly implemented.
• add a new blog post /_posts/2017-12-21-test-code-snippets.md to test out the fix. If you now click on the code snippet, it now stays still and not collapsed. (i.e. proving the fix works).

[Atlas7]

Please review this commit relating to this issue on code snippet collapse. I've tested it locally by doing a jekyll serve on a mac. Works fine. This is the fix I use in my own blog (that uses Jalpc!) at https://atlas7.github.io/. Note that this fix is similar to the fix that I applied to my blog.

[shabbir-hasan]

@Atlas7

Thank You for the solution.. 😄

[Atlas7]

Thank you for the merge! 👍