Verify signed identities

cache/repo_cache.go

commands/user_create.go

commands/user_key_add.go

commands/user_key_rm.go

commands/validate.go

go.mod

go.sum

identity/identity.go

identity/identity_test.go

identity/key.go

identity/key_test.go

identity/version.go

repository/git_test.go

repository/git_testing.go

validate/validator.go

validate/validator_test.go