Add documentation to run tests on Emulator

Signed-off-by: utzcoz <utzcoz@outlook.com>

README.md

@@ -60,11 +60,13 @@ Those software configurations are recommended and tested.
 
 See [Building Robolectric](http://robolectric.org/building-robolectric/) for more details about setting up a build environment for Robolectric.
 
-### build and test
+### Building
 Robolectric supports running tests against multiple Android API levels. The work it must do to support each API level is slightly different, so its shadows are built separately for each. To build shadows for every API version, run:
 
     ./gradlew clean assemble testClasses --parallel
 
+### Testing
+
 Run tests for all API levels:
 
 > The fully tests could consume more than 16G memory(total of physical and virtual memory).
@@ -75,6 +77,10 @@ Run tests for part of supported API levels, e.g. run tests for API level 26, 27,
 
     ./gradlew test --parallel -Drobolectric.enabledSdks=26,27,28
 
+Run compatibility test suites on opening Emulator:
+
+    ./gradlew connectedCheck
+
 ### Using Snapshots
 
 If you would like to live on the bleeding edge, you can try running against a snapshot build. Keep in mind that snapshots represent the most recent changes on master and may contain bugs.