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/wp.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:        "wp",
 		Description: "Path to the WordPress files",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "cache", Description: "Adds, removes, fetches, and flushes the WP Object Cache object"},
 			{Name: "add", Description: "Adds a value to the object cache"},
 			{Name: "key", Description: "Cache key"},
@@ -60,7 +60,7 @@ func init() {
 			{Name: "unapprove", Description: "Unapproves a comment"},
 			{Name: "unspam", Description: "Unmarks a comment as spam"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--path", Description: "Path to the WordPress files"},
 			{Name: "--url", Description: "Perform operation against a remote WordPress installation over HTTP"},
 			{Name: "--user", Description: "Set the WordPress user"},