rename to match naming convention of AntUnit tests

git-svn-id: https://svn.apache.org/repos/asf/ant/antlibs/dotnet/trunk@448811 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/tests/antunit/old-core.xml b/src/tests/antunit/old-core-test.xml
similarity index 100%
rename from src/tests/antunit/old-core.xml
rename to src/tests/antunit/old-core-test.xml