Add tests for models

Such tests make use of the refactored login commands, which means
that only the first tests needs to log in via the GUI, while others
benefit from the session to be restored from the cache.

In this test suite, I've also create a custom command to cleanup
all existing models on the beforeEach hook so that tests always
start in a fresh state.

cypress.json

@@ -1,4 +1,5 @@
 {
+  "apiUrl": "http://localhost:3000",
   "experimentalSessionSupport": true,
   "baseUrl": "http://localhost:9000",
   "fixturesFolder": false,

cypress/integration/models.spec.js

@@ -0,0 +1,56 @@
+describe('Models', () => {
+  beforeEach(() => {
+    cy.intercept('get', '/models?userId=*').as('getUserModels')
+    cy.login()
+    cy.visit('/#!/main')
+    cy.cleanUpUserModels()
+    cy.contains('a', 'Nova Modelagem').click()
+    cy.get('create-model-modal').should('be.visible')
+  })
+
+  it('opens and closes the "New Model" modal', () => {
+    cy.contains('button', 'Cancelar').click()
+    cy.get('create-model-modal').should('not.exist')
+  })
+
+  it('alerts when clicking SAVE without filling the title', () => {
+    cy.contains('button', 'Salvar').click()
+    cy.get('#name').should('have.class', 'error')
+  })
+
+  context('Model creation', () => {
+    const modelTitle = 'User'
+
+    beforeEach(() => cy.get('#name').type(modelTitle))
+
+    it('creates a conceptual model', () => {
+      cy.contains('button', 'Salvar').click()
+
+      cy.contains('h2', `Modelo conceitual de: ${modelTitle}`)
+        .should('be.visible')
+    })
+
+    it('creates a logical model', () => {
+      cy.get('.modelselect').click()
+      cy.contains('li span', 'Lógico').click()
+      cy.contains('button', 'Salvar').click()
+
+      cy.contains('h2', `Modelo lógico de: ${modelTitle}`)
+        .should('be.visible')
+    })
+  })
+})
+
+Cypress.Commands.add('cleanUpUserModels', () => {
+  cy.wait('@getUserModels').then(userModels => {
+    cy.request('GET', userModels.response.url).then(userModelsResponse => {
+      userModelsResponse.body.forEach(model => {
+        cy.request(
+          'DELETE',
+          `${Cypress.config('apiUrl')}/models/:modelId?modelId=${model._id}`
+        )
+      })
+    })
+  })
+  cy.reload()
+})