Update TestEnvironment to explicitly set "HOME" to be empty so it gets autofilled

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)

integration-cli/docker_cli_run_test.go

@@ -657,7 +657,7 @@ func TestRunTwoConcurrentContainers(t *testing.T) {
 }
 
 func TestEnvironment(t *testing.T) {
-	cmd := exec.Command(dockerBinary, "run", "-h", "testing", "-e=FALSE=true", "-e=TRUE", "-e=TRICKY", "busybox", "env")
+	cmd := exec.Command(dockerBinary, "run", "-h", "testing", "-e=FALSE=true", "-e=TRUE", "-e=TRICKY", "-e=HOME=", "busybox", "env")
 	cmd.Env = append(os.Environ(),
 		"TRUE=false",
 		"TRICKY=tri\ncky\n",