Added tests for selecting camera; related to #128

src/common/mediaDevices.js

@@ -0,0 +1,17 @@
+
+export function enumerateDevices() {
+    if (navigator.mediaDevices
+            && typeof navigator.mediaDevices.enumerateDevices === 'function') {
+        return navigator.mediaDevices.enumerateDevices();
+    }
+    return Promise.reject(new Error('enumerateDevices is not defined'));
+};
+
+export function getUserMedia(constraints) {
+    if (navigator.mediaDevices
+            && typeof navigator.mediaDevices.getUserMedia === 'function') {
+        return navigator.mediaDevices
+            .getUserMedia(constraints);
+    }
+    return Promise.reject(new Error('getUserMedia is not defined'));
+}