Bump base64 dependency to 0.21.0

[tgonzalezorlandoarm]

Formatting error to fix :)

[tgonzalezorlandoarm]

e2e_tests should have the neccesary changes as well :)

[tgonzalezorlandoarm]

Cargo.lock seems to be corrupt. If you want to update base64 to version 0.21.0, my suggestion is to run:

git reset --soft HEAD^
git restore --staged Cargo.lock
cargo update --package base64@0.21.2 --precise 0.21.0
git add Cargo.lock

And commit again

[tgonzalezorlandoarm]

LGTM Thanks!