Added test class for ShellCommand.java

Author: hiteshsondhi88

FFmpegAndroid/src/androidTest/java/com/github/hiteshsondhi88/libffmpeg/ShellCommandTest.java

@@ -0,0 +1,12 @@
+package com.github.hiteshsondhi88.libffmpeg;
+
+public class ShellCommandTest extends CommonTestCase {
+
+    public void testRun() throws Exception {
+        // TODO
+    }
+
+    public void testRunWaitFor() throws Exception {
+        // TODO
+    }
+}