Minor fix to a unittest that left text files in the project directory.

[lrzpellegrini]

Fixes a unittest that left text files in the project directory. Files are now created and destroyed in the system temp directory.

[ContinualAI-bot]

Oh no! It seems there are some PEP8 errors! 😕
Don't worry, you can fix them! 💪
Here's a report about the errors and where you can find them:

tests/test_high_level_generators.py:136:81: E501 line too long (86 > 80 characters)
1       E501 line too long (86 > 80 characters)

[coveralls]

Pull Request Test Coverage Report for Build 2753944502

• 10 of 10 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.008%) to 72.277%

---

Totals
Change from base Build 2696355092:	0.008%
Covered Lines:	12772
Relevant Lines:	17671

---

💛 - Coveralls