build: run cucumber tests using NPM scripts instead of Grunt

The main reason for this change is to be able to update Cucumber library as `grunt-cucumberjs` (mavdi/grunt-cucumberjs#110) does not support cucumber@4 and looks pretty abandoned.

Grunt ecosystem is not very active for a while, so we can expect more issues of this sort in the future. Because of this and to keep docs consistent I've also added NPM scripts to run other test types (for now they just proxy to Grunt) and removed Grunt examples from the documentation.

In the next PR I will update `cucumber` and perform some cleanup of the step definitions.

cucumber.js

@@ -0,0 +1,14 @@
+// Shared configuration for Cucumber.js tests.
+// See https://github.com/cucumber/cucumber-js/blob/master/docs/cli.md#profiles
+const options = [
+  '--format progress',
+  '--require test/e2e/support/env.js',
+  '--require test/e2e/support/world.js',
+  '--require test/e2e/step_definitions/core_steps.js',
+  '--require test/e2e/step_definitions/hooks.js',
+  '--tags "not @not-jenkins"'
+]
+
+module.exports = {
+  'default': options.join(' ')
+}

docs/dev/02-making-changes.md

@@ -23,29 +23,29 @@ Here are some tips on how to set up a Karma workspace and how to send a good pul
 * Install for development. Use a recent npm version, ignore peerdep warnings
   ```bash
   $ npm install
-  $ rm -rf node_modules/karma
-  $ cd node_modules
-  $ ln -s ../ karma
-  $ cd ../
-  $ grunt browserify
+
+  $ npm run init
+  # or if you're on Windows
+  $ npm run init:windows
+
+  $ npm build
   ```
 
 ## Testing and Building
 - Run the tests via:
   ```bash
   $ npm test
-  # or if you have grunt-cli installed globally you can also
-  $ grunt test:unit
-  $ grunt test:e2e
-  $ grunt test:client
-
-  # All tests.
-  $ grunt test
+  # or you can run test suits individually
+  $ npm run test:unit
+  $ npm run test:e2e
+  $ npm run test:client
   ```
 
 - Lint the code via:
   ```bash
   $ npm run lint
+  # or you can also apply auto-fixes where possible
+  $ npm run lint:fix
   ```
 
 - Build the client code via:

gruntfile.js

@@ -20,8 +20,7 @@ module.exports = function (grunt) {
     },
     test: {
       unit: 'mochaTest:unit',
-      client: 'test/client/karma.conf.js',
-      e2e: 'cucumberjs:ci'
+      client: 'test/client/karma.conf.js'
     },
     watch: {
       client: {
@@ -43,30 +42,6 @@ module.exports = function (grunt) {
         ]
       }
     },
-    cucumberjs: {
-      options: {
-        steps: 'test/e2e/step_definitions',
-        format: 'progress',
-        require: ['test/e2e/support/env.js', 'test/e2e/support/world.js']
-      },
-      all: 'test/e2e/*.feature',
-      current: {
-        files: {
-          src: 'test/e2e/*.feature'
-        },
-        options: {
-          tags: '@current'
-        }
-      },
-      ci: {
-        files: {
-          src: 'test/e2e/*.feature'
-        },
-        options: {
-          tags: 'not @not-jenkins'
-        }
-      }
-    },
     eslint: {
       options: {
         quiet: true