This removes the github.com/pkg/errors package in favor of the official
error wrapping in go 1.13.
Signed-off-by: Andrew Rynhard <andrew@andrewrynhard.com>
Instead of passing around a struct, it is better if we pass around an
interface that describes the behavior we want. The Runtime interface
provides a common place to describe runtime specific parameters. This
initial implementation offers the runtime mode, the platform specifics,
and the config.
Signed-off-by: Andrew Rynhard <andrew@andrewrynhard.com>
