Fixed path for extra_template_inputs

[zhieejhia93]

Description

This PR fixes the path for extra_template_inputs. Previously the code would overwrite the template files in the original directory instead of creating new files in the temporary directory.

Fixes #108

Checklist:

• My code follows the style guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation (if applicable)
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• I have updated the CHANGELOG.md file (if applicable)
• I have successfully run examples that may be affected by my changes

[zhieejhia93]

@paulromano @nstauff Please review.

[paulromano]

Thanks for fixing this @zhieejhia93!