Increase browser requirements

- Firefox 60 ESR (released 2018-05-09)
- Chrome 65 (released 2018-03-06)
- Opera 52 (released 2018-03-14)
- Safari 11 (released 2017-09-19)

Support for Firefox ESR 52 was dropped on September 5, 2018. Using
out-of-date browsers should be discouraged as they pose a security risk.

dist/babelify-config.js

@@ -3,9 +3,9 @@ const babelifyConfig = {
         ['@babel/preset-env', {
             'useBuiltIns': 'entry',
             'targets': {
-                'firefox': 50,
-                'chrome': 45,
-                'opera': 32,
+                'firefox': 60,
+                'chrome': 65,
+                'opera': 52,
                 'safari': 11,
             },
         }],

src/app.ts

@@ -76,9 +76,9 @@ angular.module('3ema', [
 
 // Constants to be used by controllers
 .constant('BROWSER_MIN_VERSIONS', {
-    FF: 50,
-    CHROME: 45,
-    OPERA: 32,
+    FF: 60,
+    CHROME: 65,
+    OPERA: 52,
     SAFARI: 11,
 })