Make it work in modern versions.

[paper42]

1. Solves DeprecationWarning in regexes using raw strings.
2. Solves issue CommonMark Import error #13 - renames module CommonMark to commonmark - CommonMark was an alias, but it was removed in commit 4ee43fbfbc0e3c6f42b8ddb31f2d12cdc3d34c04

[coveralls]

Pull Request Test Coverage Report for Build 22

• 5 of 5 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

---

Totals
Change from base Build 20:	0.0%
Covered Lines:	533
Relevant Lines:	533

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 22

• 5 of 5 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

---

Totals
Change from base Build 20:	0.0%
Covered Lines:	533
Relevant Lines:	533

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 22

• 5 of 5 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

---

Totals
Change from base Build 20:	0.0%
Covered Lines:	533
Relevant Lines:	533

---

💛 - Coveralls

[sunainapai]

Hi @PaperMountainStudio, Sorry for the delay in merging this pull request. I was away for a while. Thank you for the fixes. I have merged them into master now.

[paper42]

Thanks 😉