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/bundle.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:        "bundle",
 		Description: "Gem",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "install", Description: "Install the gems specified by the Gemfile or Gemfile.lock"},
 			{Name: "update", Description: "Update dependencies to their latest versions"},
 			{Name: "exec", Description: "Execute a command in the context of the bundle"},
@@ -26,7 +26,7 @@ func init() {
 			{Name: "clean", Description: "Clean up unused gems in your Bundler directory"},
 			{Name: "doctor", Description: "Display warnings about common problems"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--binstubs", Description: "Create binstubs in dir"},
 			{Name: "--clean", Description: "Remove unused gems after install"},
 			{Name: "--deployment", Description: "For Production and CI use"},