Update fetch calls to use axios instead

[atdservicebot]

Migrated from atd-knack-signs-markings #42

[atdservicebot]

From amenity on 2019-07-01:

Might never encounter if users are using modern IE browsers. Will assign impact based on user testing.

[atdservicebot]

From sergiogcx on 2019-07-01:

Copying a comment I made in Slack:

@mateo @Mike Dilley as an alternative to axios, we can always use a polyfill to address old browser compatibility:
ie: https://github.com/developit/unfetch

@mateoclarke @mddilley