Android Unable to find instrumentation target package

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.mayi.test.dao"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="8" />
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <uses-library android:name="android.test.runner"/> <!--不可修改-->
        <activity android:name=".MainActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <instrumentation android:name="android.test.InstrumentationTestRunner" <!--不可修改-->
	android:targetPackage="com.mayi.test.dao" <!--跟package包名相同-->
	android:label="Testing"><!--可写可不写-->
	</instrumentation>
</manifest>