Make hoodie run on travis-ci

Test logs > 4MB, which is a limit for travis-ci. Reducing the logs by setting appropriate log levels for tests
Add sudo: required on travis.yml to get more memory for running the tests. (https://github.com/travis-ci/travis-ci/issues/5926)
Fixed requirement that fsclient.lastDataFileForDataset always returns files in order

pom.xml

@@ -130,6 +130,16 @@
                 <artifactId>maven-release-plugin</artifactId>
                 <version>2.5.3</version>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>${maven-surefire-plugin.version}</version>
+                <configuration>
+                    <systemPropertyVariables>
+                        <log4j.configuration>file:${project.build.testOutputDirectory}/log4j-surefire.properties</log4j.configuration>
+                    </systemPropertyVariables>
+                </configuration>
+            </plugin>
         </plugins>
         <pluginManagement>
             <plugins>
@@ -141,10 +151,6 @@
                     <artifactId>maven-jar-plugin</artifactId>
                     <version>${maven-jar-plugin.version}</version>
                 </plugin>
-                <plugin>
-                    <artifactId>maven-surefire-plugin</artifactId>
-                    <version>${maven-surefire-plugin.version}</version>
-                </plugin>
                 <plugin>
                     <groupId>org.codehaus.mojo</groupId>
                     <artifactId>cobertura-maven-plugin</artifactId>