Please update for Docker 18.03.1

[onlyjob]

This library FTBFS with recent version of Docker client.
The following patch appears to fix the problem:

--- a/loader/loader.go
+++ b/loader/loader.go
@@ -11,9 +11,9 @@

        "github.com/aanand/compose-file/interpolation"
        "github.com/aanand/compose-file/schema"
        "github.com/aanand/compose-file/types"
-       "github.com/docker/docker/runconfig/opts"
+       "github.com/docker/cli/opts"
        units "github.com/docker/go-units"
        shellwords "github.com/mattn/go-shellwords"
        "github.com/mitchellh/mapstructure"
        yaml "gopkg.in/yaml.v2"