RUSTSEC-2018-0005: Uncontrolled recursion leads to abort in deserialization

[github-actions]

Uncontrolled recursion leads to abort in deserialization

Details
Package	serde_yaml
Version	0.7.5
URL	dtolnay/serde-yaml#105
Date	2018-09-17
Patched versions	>= 0.8.4
Unaffected versions	< 0.6.0-rc1

Affected versions of this crate did not properly check for recursion
while deserializing aliases.

This allows an attacker to make a YAML file with an alias referring
to itself causing an abort.

The flaw was corrected by checking the recursion depth.

See advisory page for additional details.

[madadam]

Depends on https://github.com/maidsafe/parsec/issues/365

[madadam]

We no longer depend on serde_yaml.