SP-260 Fix failing de/serialization tests

Author: bobbrodie

pom.xml

@@ -127,6 +127,9 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
                 <version>2.22.2</version>
+                <configuration>
+                    <argLine>-Duser.timezone=UTC</argLine>
+                </configuration>
             </plugin>
         </plugins>
     </build>

src/test/java/com/bitpay/sdk/util/DateDeserializerTest.java

@@ -16,7 +16,6 @@ public class DateDeserializerTest {
     @Test
     public void it_should_deserialize_date() throws IOException {
         // given
-        System.setProperty("user.timezone", "UTC");
         DateDeserializer testedClass = new DateDeserializer();
         JsonParser jsonParser = Mockito.mock(JsonParser.class);
         DeserializationContext deserializationContext = Mockito.mock(DeserializationContext.class);

src/test/java/com/bitpay/sdk/util/DateSerializerTest.java

@@ -15,7 +15,6 @@ public class DateSerializerTest {
     @Test
     public void it_should_serialize_date() throws IOException {
         // given
-        System.setProperty("user.timezone", "UTC");
         DateSerializer testedClass = new DateSerializer();
         JsonGenerator jsonGenerator = Mockito.mock(JsonGenerator.class);
         SerializerProvider serializerProvider = Mockito.mock(SerializerProvider.class);