fix(types): Add type definition for getCurrentAmplitude (#241)

* ci(travis): Update Travis CI configuration for new paramedic (#227)

* Update Travis CI configuration for new paramedic

* Update .travis.yml

* remove failing platforms

*  Add type definition for getCurrentAmplitude


Co-authored-by: Jan Piotrowski <piotrowski+git@gmail.com>
diff --git a/types/index.d.ts b/types/index.d.ts
index 3e47fb9..18f4496 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -28,6 +28,14 @@
  */
 interface Media {
     /**
+     * Returns the current amplitude within an audio file.
+     * @param mediaSuccess The callback that is passed the current amplitude (0.0 - 1.0).
+     * @param mediaError   The callback to execute if an error occurs.
+     */
+    getCurrentAmplitude(
+        mediaSuccess: (amplitude: number) => void,
+        mediaError?: (error: MediaError) => void): void;
+    /**
      * Returns the current position within an audio file. Also updates the Media object's position parameter.
      * @param mediaSuccess The callback that is passed the current position in seconds.
      * @param mediaError   The callback to execute if an error occurs.
@@ -81,4 +89,4 @@
 interface IosPlayOptions {
     numberOfLoops?: number;
     playAudioWhenScreenIsLocked?: boolean;
-}
\ No newline at end of file
+}