build all backends

recent changes mean users can select backend at run time. make backends
opt-out in spackage.

packages/sdskeyval/package.py

@@ -36,8 +36,8 @@ class Sdskeyval(AutotoolsPackage):
 
 
     variant('bwtree', default=True, description="Enable BwTree keyval backend")
-    variant('bdb', default=False, description="Enable Berkely DB keyval backend")
-    variant('leveldb', default=False, description="Enable LevelDB keyval backend")
+    variant('bdb', default=True, description="Enable Berkely DB keyval backend")
+    variant('leveldb', default=True, description="Enable LevelDB keyval backend")
     variant('lmdb', default=False, description="Enable lmdb keyval backend")
 
     depends_on('margo', type=("build", "link", "run"))