doc: update README

README.md

@@ -130,10 +130,8 @@ The first one execute java command with call graph tool to create à call graph
 
 #### How to write tests 
 
-The rules to respect are:
-
-- You must write only one energy test per file test class
-- You have to add this annotation on each energy test like 
+You have to add the annotation `@EnergyTest` on each energy, instead of classical `@Test` annotation.
+Following an example:  
 
 	//...
 

src/test/java/org/powerapi/jjoules/AbstractTest.java

@@ -1,7 +1,6 @@
 package org.powerapi.jjoules;
 
 import org.junit.After;
-import org.junit.jupiter.api.AfterAll;
 
 import java.io.File;
 import java.util.ArrayList;