Merge pull request #46 from Johnny1994/dev

QNDroidRTCDemo/app/build.gradle

QNDroidRTCDemo/app/libs/qndroid-rtc-2.3.1.jar

.../java/com/qiniu/droid/rtc/demo/activity/RoomActivity.java

...va/com/qiniu/droid/rtc/demo/activity/SettingActivity.java

.../src/main/java/com/qiniu/droid/rtc/demo/utils/Config.java

QNDroidRTCDemo/app/src/main/res/layout/activity_setting.xml

QNDroidRTCDemo/app/src/main/res/values/strings.xml

README.md

ReleaseNotes/release-notes-2.3.1.md

releases/qndroid-rtc-2.3.1.jar