Added 2 phases:
1. secret-reencrypt - This phase can be used to
reecnrypt the existing secrets with new key.
To do so SOPS_IMPORT_PGP must contain
old public key and new private key (but
may also include other data).
SOPS_PGP_FP must contain fingerprint of
new private key.
2. secret-show - This phase may be useful for some users
that need to see what generated by secret-generate phase.
Disabled SOPS debug by default.
To enable it back run commands with
env variable DEBUG_SOPS_GPG=true
Change-Id: Id7fe13d6943d386577df25dba4aaa83e62e58980
a7e332f9ec