* Allow for the DNSimple account ID to be specified via the dnssimple.accountID value
* Allow for the DNSimple account ID to be manually specified via the DNSIMPLE_ACCOUNT_ID environment variable
Fix incorrect variable specification in main.go
* Allow for the DNSimple account ID to be manually specified via the DNSIMPLE_ACCOUNT_ID environment variable
Fix missing return of nil in main.go
* Fix incorrect double-declaration of env section in deployment.yaml
* Fix incorrect logic when handling DNSIMPLE_ACCOUNT_ID environment variable
* The client.Zones.GetZone check isn't needed in the getExistingRecord function and it prevents User API tokens from being used for authentication - only Account API tokens would work
* Incorporate changes from https://github.com/puzzle/cert-manager-webhook-dnsimple/pull/29 so that the DNSimple accountID may be obtained from the Issuer config if a DNSimple User API token is being used
* Remove unused variable DnsimpleAccountId
* Fix deploy/dnsimple/templates/deployment.yaml - DNSIMPLE_ACCOUNT_ID environment variable doesn't do anything anymore so we can delete it
* Pass the .Values.dnsimple.accountID value down to the staging and production ClusterIssuer configs
* Update README.md with documentation on the dnsimple.accountID parameter
* The ClusterIssuer configs must quote the accountID value so that it is interpreted as a string and not as a number
* Fix indentation level of imagePullSecret in deployment.yaml
