Updates the following dependencies to latest:
* Masterminds/semver
* Masterminds/sprig
* ghodss/yaml
* satori/go.uuid -> google/uuid
* huandu/xstrings
* imdario/mergo
* crypto
* alecthomas/kingpin.v2
* yaml.v2
As usual Go libraries are YOLO-versioned, so who knows what changed
here. I'll be going through `sprig` at least to add that to the
changelog.
This relates to #152.
Removes the old error handling library and switches to plain
fmt.Errorf calls.
There are several reasons for this:
* There are no useful types or handling here anyways, so output format
is the only priority.
* Users don't care about getting stacktraces.
* My emotional wellbeing.
Fin de siècle.
