feat: add outdated=dependencies command

Author: zdm

lib/package.js

@@ -857,21 +857,31 @@ export default class Package {
                         res = await this.npm.getPackageVersions( dependency.name );
 
                         if ( res.ok ) {
-                            let latest;
+                            let latest, next;
 
                             for ( let version of res.data ) {
                                 version = new SemanticVersion( version );
 
-                                if ( latest ) {
-                                    if ( version.gt( latest ) ) latest = version;
+                                if ( next ) {
+                                    if ( version.gt( next ) ) next = version;
                                 }
                                 else {
-                                    latest = version;
+                                    next = version;
+                                }
+
+                                if ( !version.isPreRelease ) {
+                                    if ( latest ) {
+                                        if ( version.gt( latest ) ) latest = version;
+                                    }
+                                    else {
+                                        latest = version;
+                                    }
                                 }
                             }
 
                             res = result( 200, {
                                 latest,
+                                next,
                             } );
                         }