Problem: No client side tests (#1001)

Solution: Implement webdriverio + headless chrome client side tests in Travis CI and include an example test for the home page. (`homepage.spec.js`)

.travis.yml

@@ -2,6 +2,9 @@ sudo: required
 
 language: node_js
 
+addons:
+  chrome: stable
+
 node_js: 
   - '8'
 
@@ -11,6 +14,9 @@ before_install:
   - export LC_ALL=C
   - curl https://install.meteor.com | /bin/sh
   - export PATH="$HOME/.meteor:$PATH"
+  - npm install selenium-standalone@latest -g
+  - selenium-standalone install
+  - selenium-standalone start &
 
 cache:
   directories:
@@ -19,6 +25,10 @@ cache:
 
 before_script:
   - meteor npm install
+  - meteor npm install --unsafe wdio-mocha-framework webdriverio assert
+  - meteor --production &
+  - sleep 300 # wait for Meteor to start, it takes some time, 5 minutes should be sufficient
 
 script:
-  - meteor test --driver-package=meteortesting:mocha --once 
+  - ./node_modules/.bin/wdio wdio.conf.js
+  - meteor test --driver-package=meteortesting:mocha --once --port 5000

imports/ui/pages/returnedCurrencies/homepage.ui-test.js

@@ -0,0 +1,13 @@
+const assert = require('assert')
+
+const baseUrl = 'http://localhost:3000' // baseUrl of the app we are testing, it's localhost here, as we're starting a local server in Travis CI cycle
+
+// see the full webdriverio browser API here: http://webdriver.io/api.html
+describe('Home page', function () {
+    it('Currencies should render properly', function () {
+        browser.url(`${baseUrl}/`) // navigate to the home route `/`
+        browser.pause(2000) // let it load, wait for 2 seconds
+        assert(browser.isExisting('.currency-card'), true) // check if at least one currency card has rendered, isExisting === $() !== undefined
+        assert(browser.isVisible('.currency-card'), true) // check if at least one currency card is visible on the page isVisible === $().is(':visible')
+    })
+})

wdio.conf.js

@@ -0,0 +1,27 @@
+exports.config = {
+    specs: ['./imports/**/*.ui-test.js'],
+    exclude: [],
+    maxInstances: 10,
+    capabilities: [{
+        browserName: 'chrome',
+        chromeOptions: {
+            args: ['--headless', '--disable-gpu', '--window-size=1280,800'],
+            binary: '/usr/bin/google-chrome-stable'
+        }
+    }],
+    sync: true,
+    logLevel: 'silent',
+    coloredLogs: true,
+    deprecationWarnings: true,
+    bail: 0,
+    screenshotPath: './screens/',
+    baseUrl: 'http://localhost:3000',
+    waitforTimeout: 10000,
+    connectionRetryTimeout: 90000,
+    connectionRetryCount: 3,
+    framework: 'mocha',
+    reporters: ['dot'],
+    mochaOpts: {
+        ui: 'bdd'
+    }
+}