Fix JOSE Rotation (#72)

Evidently cert-manager doesn't actually rotate the private key unless
you tell it to, which is kinda annoying as you get the same public key
for subsequent certificates, and the same key ID, which bascially
prevents authentication from ever working!

charts/identity/templates/identity/certificate.yaml

@@ -10,6 +10,7 @@ spec:
     algorithm: ECDSA
     encoding: PKCS8
     size: 521
+    rotationPolicy: Always
   commonName : Unikorn Server JOSE Key
   secretName: unikorn-identity-jose-tls
   # Twice the duration to caterfor overlap, then convert to hours (2 * 24).