integration-cli: generate unix-style volume paths

Some tests in `docker_api_containers_test.go` assume the
docker daemon is running at the same machine as the cli
and uses `ioutil.TempDir` to create temp dirs and use them
in the test.

On windows ioutil.TempDir and os.TempDir would create win-style
paths and pass them to daemon. Instead, I hardcoded `/tmp/` and
generate some random path manually and allow daemon to create
the directory.

Fixes tests:
- TestContainerApiStartVolumeBinds
- TestContainerApiStartDupVolumeBinds
- TestVolumesFromHasPriority

Downside:
- Does not clean the temp dirs generated on the remote daemon
  machine unless delete container deletes them.

Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>

integration-cli/utils.go

@@ -10,6 +10,7 @@ import (
 	"net/http/httptest"
 	"os"
 	"os/exec"
+	"path"
 	"reflect"
 	"strings"
 	"syscall"
@@ -241,6 +242,12 @@ func makeRandomString(n int) string {
 	return string(b)
 }
 
+// randomUnixTmpDirPath provides a temporary unix path with rand string appended.
+// does not create or checks if it exists.
+func randomUnixTmpDirPath(s string) string {
+	return path.Join("/tmp", fmt.Sprintf("%s.%s", s, makeRandomString(10)))
+}
+
 // Reads chunkSize bytes from reader after every interval.
 // Returns total read bytes.
 func consumeWithSpeed(reader io.Reader, chunkSize int, interval time.Duration, stop chan bool) (n int, err error) {