remove TestObjectFactory and fix pom.xml

See "Singleton and unit testing"
https://stackoverflow.com/questions/8256989/singleton-and-unit-testing

> With singletons – the bad thing is that the getInstance() method is globally accessible. That means that you usually call it from within a class, instead of depending on an interface you can later mock. That's why it's impossible to replace it when you want to test your SUT.  The solution is not to use the sneaky public static MySingleton getInstance() method, but to depend on an interface your class needs to work with. Do that, and you can pass in test doubles whenever you need to.

pom.xml

@@ -88,30 +88,6 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>3.2.5</version>
-                <configuration>
-                    <forkCount>3</forkCount>
-                    <reuseForks>true</reuseForks>
-                    <argLine>-Xmx1024m</argLine>
-                    <properties>
-                        <property>
-                            <name>junit</name>
-                            <value>false</value>
-                        </property>
-                    </properties>
-                    <threadCount>1</threadCount>
-                </configuration>
-                <dependencies>
-                    <dependency>
-                        <groupId>org.apache.maven.surefire</groupId>
-                        <artifactId>surefire-junit47</artifactId>
-                        <version>3.2.5</version>
-                    </dependency>
-                    <dependency>
-                        <groupId>org.apache.maven.surefire</groupId>
-                        <artifactId>surefire-testng</artifactId>
-                        <version>3.2.5</version>
-                    </dependency>
-                </dependencies>
             </plugin>
             <plugin>
                 <groupId>pl.project13.maven</groupId>
@@ -248,18 +224,6 @@
         </plugins>
     </build>
     <dependencies>
-        <dependency>
-            <groupId>com.github.caciocavallosilano</groupId>
-            <artifactId>cacio-tta</artifactId>
-            <version>1.10</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.testng</groupId>
-            <artifactId>testng</artifactId>
-            <version>6.14.3</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>