Fix iOS keyboard input. (#27)

* Fixed iOS keyboard input bug caused by iOS update.

ambient.d.ts

@@ -0,0 +1,11 @@
+// noinspection JSUnusedGlobalSymbols
+
+interface String {
+  /**
+   * Gets a substring beginning at the specified location and having the specified length.
+   * (deprecation removed)
+   * @param from The starting position of the desired substring. The index of the first character in the string is zero.
+   * @param length The number of characters to include in the returned substring.
+   */
+  substr(from: number, length?: number): string;
+}

karma.conf.js

@@ -16,10 +16,10 @@ module.exports = function (config) {
       clearContext: false // leave Jasmine Spec Runner output visible in browser
     },
     coverageIstanbulReporter: {
-      dir: require('path').join(__dirname, 'coverage'), reports: [ 'html', 'lcovonly' ],
+      dir: require('path').join(__dirname, 'coverage'), reports: ['html', 'lcovonly'],
       fixWebpackSourcePaths: true
     },
-    
+
     reporters: ['progress', 'kjhtml'],
     port: 9876,
     colors: true,