add allowArray to relations' create remoteMethod

this is needed because we added allowArray flag to persisted model's
remoteMethod, but when relations try to rebuild such methods, it does
not carry over such flags

lib/model.js

@@ -668,7 +668,13 @@ module.exports = function(registry) {
     define('__create__' + scopeName, {
       isStatic: isStatic,
       http: {verb: 'post', path: '/' + pathName},
-      accepts: {arg: 'data', type: 'object', model: toModelName, http: {source: 'body'}},
+      accepts: {
+        arg: 'data',
+        type: 'object',
+        allowArray: true,
+        model: toModelName,
+        http: {source: 'body'},
+      },
       description: format('Creates a new instance in %s of this model.', scopeName),
       accessType: 'WRITE',
       returns: {arg: 'data', type: toModelName, root: true},

test/model.test.js

@@ -166,6 +166,72 @@ describe.onServer('Remote Methods', function() {
           done();
         });
     });
+
+    it('creates related models', function(done) {
+      User.create({first: 'Bob'}, function(err, res) {
+        expect(res).to.have.property('id');
+        var aPost = {title: 'A story', content: 'Once upon a time'};
+        request(app)
+          .post('/users/' + res.id + '/posts')
+          .send(aPost)
+          .expect('Content-Type', /json/)
+          .expect(200)
+          .end(function(err, result) {
+            if (err) return done(err);
+            expect(result.body).to.have.property('id');
+            expect(result.body).to.have.property('title', aPost.title);
+            expect(result.body).to.have.property('content', aPost.content);
+            done();
+          });
+      });
+    });
+
+    it('creates array of hasMany models', function(done) {
+      User.create({first: 'Bob'}, function(err, res) {
+        expect(res).to.have.property('id');
+        var twoPosts = [
+          {title: 'One story', content: 'Content #1'},
+          {title: 'Two story', content: 'Content #2'},
+        ];
+        request(app)
+          .post('/users/' + res.id + '/posts')
+          .send(twoPosts)
+          .expect('Content-Type', /json/)
+          .expect(200)
+          .end(function(err, result) {
+            if (err) return done(err);
+            expect(result.body.length).to.eql(2);
+            expect(result.body).to.have.deep.property('[0].title', 'One story');
+            expect(result.body).to.have.deep.property('[1].title', 'Two story');
+            done();
+          });
+      });
+    });
+
+    it('rejects array of obj input for hasOne relation', function(done) {
+      var Friend = app.registry.createModel('friend', {name: String});
+      app.model(Friend, {dataSource: 'db'});
+      User.hasOne(Friend);
+
+      User.create({first: 'Bob'}, function(err, res) {
+        expect(res).to.have.property('id');
+        var twoFriends = [
+          {name: 'bob'},
+          {name: 'rob'},
+        ];
+        request(app)
+          .post('/users/' + res.id + '/friend')
+          .send(twoFriends)
+          .expect('Content-Type', /json/)
+          .expect(400)
+          .end(function(err, result) {
+            if (err) return done(err);
+            var resError = result.body.error;
+            expect(resError.message).to.match(/value(.*?)not(.*?)object(\.?)/i);
+            done();
+          });
+      });
+    });
   });
   // destoryAll is not exposed as a remoteMethod by default
   describe('Model.destroyAll(callback)', function() {