cfssl bundle produces json with "crt" instead of "cert"

The "cfssl bundle" command produces json with a "crt" element instead of a "cert".
e.g.:

```
cfssl bundle -ca-bundle ca/ca.pem \
-int-bundle intermediate/intermediate_ca.pem \
-cert myhost.pem \
| jq -r |cut -c 1-78
2019/04/19 17:13:04 [INFO] bundling certificate for CN=myhost.local.net,OU=DevOps,O=MyCompany,L=New York,ST=New York,C=US
2019/04/19 17:13:04 [WARNING] No metadata, Ubiquitous falls back to Optimal.
2019/04/19 17:13:04 [INFO] the anchoring root is CN=My CA,L=New York,ST=New York,C=US
{
"bundle": "-----BEGIN CERTIFICATE-----\nMIIEcTCCA1mgAwIBAgIUF3ZwuH+ezyy+cvss
"crl_support": false,
"crt": "-----BEGIN CERTIFICATE-----\nMIIEcTCCA1mgAwIBAgIUF3ZwuH+ezyy+cvssn5l
"expires": "2020-04-18T17:02:00Z",
"hostnames": [
"myhost.local.net"
],
"issuer": "/Country=US/Province=New York/Locality=New York/Organizati
"key": "",
"key_size": 2048,
"key_type": "2048-bit RSA",
"leaf_expires": "2020-04-18T17:02:00Z",
"ocsp": null,
"ocsp_support": false,
"root": "-----BEGIN CERTIFICATE-----\nMIIDkjCCAnqgAwIBAgIUWATVPhSR02BOuMXjIS
"signature": "SHA256WithRSA",
"status": {
"rebundled": true,
"expiring_SKIs": null,
"untrusted_root_stores": [],
"messages": [
"The bundle contains certificates signed with advanced hash functions su
"Unable to measure bundle ubiquity: No platform metadata present."
],
"code": 2
},
"subject": "/Country=US/Province=New York/Locality=New York/Organizati
}
```