feat: to allow config public for Migration model

Author: andy2046

README.md

@@ -34,7 +34,7 @@ The usage is based on the node-db-migrate project.
 
 - `enableRest`
 
-  [Boolean] : A boolean indicating wether migrate/rollback REST api methods should be exposed on the Migration model. *(default: false)*
+  [Boolean] : A boolean indicating whether migrate/rollback REST api methods should be exposed on the Migration model. *(default: false)*
 
 - `migrationsDir`
 
@@ -48,6 +48,10 @@ The usage is based on the node-db-migrate project.
 
   [Array] : ACLs to apply to Migration and MigrationMap models. *(default: [])*
 
+- `public`
+
+  [Boolean] : A boolean indicating whether Migration model should be exposed on the StrongLoop API Explorer. *(default: true)*
+
 
 ## Running Migrations
 

lib/index.js

@@ -38,6 +38,12 @@ module.exports = function(app, options) {
     migrationModelSettings.acls = migrationMapModelSettings.acls = options.acls;
   }
 
+  if (typeof options.public === "undefined") {
+    migrationModelSettings.public = migrationMapModelSettings.public = true;
+  } else {
+    migrationModelSettings.public = migrationMapModelSettings.public = options.public;
+  }
+
   // Support for loopback 2.x.
   if (app.loopback.version.startsWith(2)) {
     Object.keys(migrationModelSettings.methods).forEach(key => {