Improve a project test structure

Many test cases are scattered over test hierarchies which is hard to
answer distinctly: what the state do we have before the test? what's the
flow between test executions? and so on. Avoiding deep hierarchies
should increase a test readability.

Closes: #188

Author: nicktorwald

pom.xml

@@ -171,6 +171,12 @@
             <version>${junit.jupiter.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <version>${junit.jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-all</artifactId>

src/main/java/org/tarantool/TarantoolClusterClient.java

@@ -278,6 +278,7 @@ public synchronized void run() {
                         onInstancesRefreshed(lastInstances);
                     }
                 } catch (Exception ignored) {
+                    ignored.getCause();
                     // no-op
                 }
             }