Use alphabetical run order of tests

Change the run order of tests from "filesystem" (default) to
"alphabetical". The default run order is based on filesystem order,
which proved to be unreliable and different on different machines. This
made debugging of issues (for example #170) much harder and not
reproducible. "alphabetical" is more stable.

Author: avelanarius

pom.xml

@@ -746,6 +746,7 @@
                         <groups>${test.groups}</groups>
                         <useFile>false</useFile>
                         <argLine>-Djdk.attach.allowAttachSelf=true</argLine>
+                        <runOrder>alphabetical</runOrder>
                         <systemPropertyVariables>
                             <cassandra.version>${cassandra.version}</cassandra.version>
                             <ipprefix>${ipprefix}</ipprefix>
@@ -776,6 +777,7 @@
                     <configuration>
                         <groups>${test.groups}</groups>
                         <useFile>false</useFile>
+                        <runOrder>alphabetical</runOrder>
                         <systemPropertyVariables>
                             <cassandra.version>${cassandra.version}</cassandra.version>
                             <ipprefix>${ipprefix}</ipprefix>