1.7.0

First of all: Thank you @tomprice, @ckiee, @c4710n, @tp-la, @cole-h,
@mweinelt, for the great contributions. Very much appreciated. 🥇

It's time to cut another morph release. Besides
moving away from deprecated nix features, the following
is notably changed:

• Option uploadAt for secret provisioning.
• Added morph eval, a wrapper around nix-instantiate.
• support added for targetPort.
• Wait for mount before deploying secrets.
• Migrated assets to ldflags instead of go-bindata.