airly_sensors feedback

[acivitillo]

Here is some feedback I have by checking out your latest code:

• you can remove the files folder and move the files 1 folder up
• you don't need classes for this exercise. Using classes will make the code hard to follow
• move the datafiles in the data folder (root of this repo)
• please remove the notebook folder and move the files 2 folders up
• use copy statement of postgres, you'll need this eventually so better start now