Update axios to >=0.21.1

[Henrik Tilly]

npm audit gives me:

High │ Server-Side Request Forgery
Package │ axios
Patched in │ >=0.21.1
Dependency of │ sonos
Path │ sonos > axios
More info │ https://npmjs.com/advisories/1594

[Henrik Tilly]

Guess this relates to:
#501

[Ben Evans]

Thanks for the report, fixed by #501