Fix some issues with expiry config field.

ca/certificate-authority.go

@@ -130,6 +130,9 @@ func NewCertificateAuthorityImpl(cadb core.CertificateAuthorityDatabase, config
 		NotAfter:   issuer.NotAfter,
 	}
 
+	if config.Expiry == "" {
+		return nil, errors.New("Config must specify an expiry period.")
+	}
 	ca.ValidityPeriod, err = time.ParseDuration(config.Expiry)
 	if err != nil {
 		return nil, err

test/boulder-config.json

@@ -46,7 +46,7 @@
     "issuerCert": "test/test-ca.pem",
     "_comment": "This should only be present in testMode. In prod use an HSM.",
     "issuerKey": "test/test-ca.key",
-    "expiry": "8760h",
+    "expiry": "8760h"
   },
 
   "sa": {

test/boulder-test-config.json

@@ -45,7 +45,8 @@
     "testMode": true,
     "issuerCert": "test/test-ca.pem",
     "_comment": "This should only be present in testMode. In prod use an HSM.",
-    "issuerKey": "test/test-ca.key"
+    "issuerKey": "test/test-ca.key",
+    "expiry": "8760h"
   },
 
   "sa": {