Don't require an old version of dm-core, simply because dm-migrations…

… version hasn't been incremented

Rakefile

@@ -10,7 +10,7 @@ AUTHOR = "Paul Sadauskas"
 EMAIL  = "psadauskas@gmail.com"
 GEM_NAME = "dm-migrations"
 GEM_VERSION = DataMapper::Migration::VERSION
-GEM_DEPENDENCIES = [["dm-core", GEM_VERSION]]
+GEM_DEPENDENCIES = [["dm-core", '>0.9.5']]
 GEM_CLEAN = ["log", "pkg"]
 GEM_EXTRAS = { :has_rdoc => true, :extra_rdoc_files => %w[ README.txt LICENSE TODO ] }