robot: Run only relevant tests, push to core-*

From now on images built from this repo are the c3os core images.
c3os core images contains only the base image, framework files and the c3os agent.

This also sets up tests accordingly to run only to cover the c3os-agent.

pkg/machine/bootcmdline_test.go

@@ -23,7 +23,7 @@ var _ = Describe("BootCMDLine", func() {
 			b, err := DotToYAML(f.Name())
 			Expect(err).ToNot(HaveOccurred())
 
-			Expect(string(b)).To(Equal("baz:\n  bar: \"\"\nconfig_url: foo bar\n"))
+			Expect(string(b)).To(Equal("baz:\n    bar: \"\"\nconfig_url: foo bar\n"), string(b))
 		})
 	})
 })