ant: Let test depend on subprojects-build

This ensures that all code is (re)built when running a test. Previously,
only the app code was built (because that's where the tests live),
requiring a manual full build when changing something in arduino-core.
This could lead to confusing situations, where you would changes
something but it was not always automatically recompiled.

Author: matthijskooijman

build/build.xml

@@ -166,7 +166,7 @@
     </java>
   </target>
 
-  <target name="test" depends="subprojects-test"/>
+  <target name="test" depends="subprojects-build, subprojects-test"/>
 
   <!-- - - - - - - - - - - - - - - - - - -->
   <!-- Subprojects: Core, App, Libraries -->