Set release source and destination branches in skeleton

src/tdk/mkit.ini.skel

 [project]
     name = [macros:__JATS_SUITENAME__] JATS test suite
     tagline = [macros:__JATS_SUITENAME__] test suite in JATS format
+    relsrc = master
+    reldst = last
 
 [dist]
     tarball  = Makefile