feat(dns): add cordova-plugin-dns plugin (#2083)

* feat(cordova-plugin-dns added): Resolve hostnames into an underlying network address.

* Update index.ts

src/@ionic-native/plugins/dns/index.ts

@@ -0,0 +1,40 @@
+import { Plugin, Cordova, IonicNativePlugin } from '@ionic-native/core';
+import { Injectable } from '@angular/core';
+
+/**
+ * @name DNS
+ * @description A plugin for Apache Cordova that enables applications to manually resolve hostnames into an underlying network address. This is mostly useful for determining whether there is a problem with the device's DNS server configuration.
+ *
+ * @usage
+ * ```typescript
+ * import { DNS } from '@ionic-native/dns';
+ *
+ *
+ * constructor(private dns: DNS) { }
+ *
+ * ...
+ * this.dns.resolve(hostname)
+ *   .then(
+ *     address => console.log('Resolved ' + hostname + ' to ' + address),
+ *     error => console.log('Failed to resolve ' + hostname + ': ' + error)
+ *   );
+ *
+ * ```
+ */
+@Plugin({
+  pluginName: 'DNS',
+  plugin: 'cordova-plugin-dns',
+  pluginRef: 'cordova.plugins.dns',
+  repo: 'https://bitbucket.org/zegeba/cordova-plugin-dns',
+  platforms: ['Android']
+})
+@Injectable()
+export class DNS extends IonicNativePlugin {
+  /**
+   * Resolve hostnames into an underlying network address.
+   * @param hostname
+   * @returns {Promise<string>} Returns a promise that resolves with the resolution.
+   */
+  @Cordova()
+  resolve(hostname: string): Promise<string> { return; }
+}