make TestRunException available outiside of the package (#105)

Co-authored-by: Pavel Strunkin <[email protected]>

Author: oleg-rd

src/main/java/io/visual_regression_tracker/sdk_java/TestRunException.java

@@ -1,6 +1,6 @@
 package io.visual_regression_tracker.sdk_java;
 
-class TestRunException extends RuntimeException {
+public class TestRunException extends RuntimeException {
     public TestRunException(String errorMessage) {
         super(errorMessage);
     }