style: add blank line between imports

Author: Rosario Trischitta

src/test/java/org/heigit/ohsome/ohsomeapi/controller/GetControllerTest.java

@@ -3,6 +3,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assume.assumeTrue;
+
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.node.JsonNodeType;
 import java.io.IOException;

src/test/java/org/heigit/ohsome/ohsomeapi/controller/PostControllerTest.java

@@ -2,6 +2,7 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assume.assumeTrue;
+
 import com.fasterxml.jackson.databind.JsonNode;
 import java.io.IOException;
 import java.util.Arrays;