Run mix format and solve warnings

[wevtimoteo]

• [x] Run mix format for entire project
• [x] Solve some warnings on compiling project

[sourcelevel-bot[bot]]

SourceLevel has finished reviewing this Pull Request and has found:

• 2 possible new issues (including those that may have been commented here).
• 2 fixed issues! 🎉

See more details about this review.