Create a unified RunCommand function with Assert()

Remove some run functions and replace them with the unified run command.
Remove DockerCmdWithStdoutStderr
Remove many duplicate runCommand functions.
Also add dockerCmdWithResult()
Allow Result.Assert() to ignore the error message if an exit status is expected.
Fix race in DockerSuite.TestDockerInspectMultipleNetwork
Fix flaky test DockerSuite.TestRunInteractiveWithRestartPolicy

Signed-off-by: Daniel Nephin <dnephin@docker.com>

integration-cli/docker_api_test.go

@@ -5,13 +5,13 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/http/httputil"
-	"os/exec"
 	"strconv"
 	"strings"
 	"time"
 
 	"github.com/docker/docker/api"
 	"github.com/docker/docker/pkg/integration/checker"
+	icmd "github.com/docker/docker/pkg/integration/cmd"
 	"github.com/go-check/check"
 )
 
@@ -89,15 +89,12 @@ func (s *DockerSuite) TestApiDockerApiVersion(c *check.C) {
 	defer server.Close()
 
 	// Test using the env var first
-	cmd := exec.Command(dockerBinary, "-H="+server.URL[7:], "version")
-	cmd.Env = appendBaseEnv(false, "DOCKER_API_VERSION=xxx")
-	out, _, _ := runCommandWithOutput(cmd)
-
+	result := icmd.RunCmd(icmd.Cmd{
+		Command: binaryWithArgs([]string{"-H", server.URL[7:], "version"}),
+		Env:     []string{"DOCKER_API_VERSION=xxx"},
+	})
+	result.Assert(c, icmd.Expected{Out: "API version:  xxx", ExitCode: 1})
 	c.Assert(svrVersion, check.Equals, "/vxxx/version")
-
-	if !strings.Contains(out, "API version:  xxx") {
-		c.Fatalf("Out didn't have 'xxx' for the API version, had:\n%s", out)
-	}
 }
 
 func (s *DockerSuite) TestApiErrorJSON(c *check.C) {