Use io.open_code for reading code

[bswck]

No description provided.

[bswck]

Let me know if you prefer a version with the import inlined, __import__('io').open_code().

[jaraco]

Looks good. Can you explain briefly what motivated this change? I read the docs for open_code and it says the behavior is the same (for an absolute path).

[bswck]

I mistakenly claimed that it's a recommended solution.
It's not.

So the only value I can see in this PR is very relative to what are our values:

• it can be educative, as the io.open_code function isn't popular
• it can be less readable, as the io.open_code function isn't popular

I leave the decision up to you (not like I have to--the decision was already yours ever since).

A decision that has not much of a meaning to the outcome of the code... I think.
But running into io.open_code, and then discussing this PR with my friends, helped me find myself again.

Oh gosh do I love computer science.

[jaraco]

Okay. I normally would say not to changes that have little impact. In this case, because open_code implies mode='rb', I like it better. Let's merge it.