Appending to .env makes notebook 05 brittle

[marabout2015]

Appending to the .env file makes notebook 05 brittle.

• Unless the cell starts with a blank line or the previous write to the .env ended with a blank line, there can be unexpected concatenations of the cell contents.
• If the appending cell is run multiple times, the contents of the cell will get appended multiple times to the .env file. However, unless the reading command is "%dotenv -o", changes to the cell content will not produce updates to the shell's environment.

[marabout2015]

Resolved by using dotenv functions to add values to the dotenv file.

[fboylu]

thanks Mario.