fakejira: use `Key` instead of `ID` for `UpdateIssue`
fakejira: use `Key` instead of `ID` for `UpdateIssue`

Jira requires the `Key`, not the `ID` when using `UpdateIssue`. As the
Jira server fails if provided the `ID`, but not the `Key`, the
`fakejira` client should be updated to reflect this.

BenTheElder/test-infra,jessfraz/test-infra,jessfraz/test-infra,dims/test-infra,jessfraz/test-infra,jessfraz/test-infra,cjwagner/test-infra,michelle192837/test-infra,cblecker/test-infra,cjwagner/test-infra,cjwagner/test-infra,dims/test-infra,kubernetes/test-infra,cblecker/test-infra,jessfraz/test-infra,cjwagner/test-infra,kubernetes/test-infra,cblecker/test-infra,kubernetes/test-infra,cblecker/test-infra,cjwagner/test-infra,jessfraz/test-infra,cjwagner/test-infra,BenTheElder/test-infra,kubernetes/test-infra,BenTheElder/test-infra,michelle192837/test-infra,kubernetes/test-infra,michelle192837/test-infra,kubernetes/test-infra,cblecker/test-infra,dims/test-infra,BenTheElder/test-infra,BenTheElder/test-infra,michelle192837/test-infra,dims/test-infra,BenTheElder/test-infra,cblecker/test-infra,dims/test-infra,michelle192837/test-infra,michelle192837/test-infra,dims/test-infra