oeqa/runtime/cases: Improve test dependency information

Add the OEHasPackage decorator to a variety of tests so they determine
automatically if they should run against a given image.

To ensure tests can do this we need to move target operations such
as scp commands into the tests and out of the class startup/teardown.

(From OE-Core rev: 60d6580b85714b8960a964e775d76a7f937f5e5a)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/runtime/cases/df.py

@@ -1,11 +1,13 @@
 from oeqa.runtime.case import OERuntimeTestCase
 from oeqa.core.decorator.depends import OETestDepends
 from oeqa.core.decorator.oeid import OETestID
+from oeqa.runtime.decorator.package import OEHasPackage
 
 class DfTest(OERuntimeTestCase):
 
     @OETestID(234)
     @OETestDepends(['ssh.SSHTest.test_ssh'])
+    @OEHasPackage(['coreutils', 'busybox'])
     def test_df(self):
         cmd = "df / | sed -n '2p' | awk '{print $4}'"
         (status,output) = self.target.run(cmd)