refactor(commands): separate commands and its core into two folders (#32)

- I think it would be better if one for commands only, one for the spec
handling core logic so people won't be confused by the core logic inside
the commands folder (cleaner I guess)
- Regen docs

commands/sys/pro.go

@@ -1,14 +1,14 @@
 package sys
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "pro",
 		Description: "Manage Ubuntu Pro services from Canonical",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "attach", Description: "Connect an Ubuntu Pro support contract to this machine"},
 			{Name: "collect-logs", Description: "Create a tarball with all relevant logs and debug data"},
 			{Name: "detach", Description: "Remove Ubuntu Pro from this machine"},
@@ -18,7 +18,7 @@ func init() {
 			{Name: "refresh", Description: "Refresh contract and service details from Canonical"},
 			{Name: "status", Description: "Report current status of Ubuntu Pro services on system"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--no-auto-enable", Description: "Disable  the  automatic enablement of recommended entitlements"},
 			{Name: "--attach-config", Description: "Provide a file with configuration options"},
 			{Name: "-o", Description: "Path for tarball. Uses ua_logs.tar.gz in current directory if not specified"},