Clean more build utils in integration cli

- Remove deprecated buildImage* functions
- Rename buildImageNew to buildImage
- Use *check.C in fakeContext* setup and in getIdByName

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

integration-cli/docker_cli_exec_test.go

@@ -473,13 +473,9 @@ func (s *DockerSuite) TestExecWithImageUser(c *check.C) {
 	// Not applicable on Windows
 	testRequires(c, DaemonIsLinux)
 	name := "testbuilduser"
-	_, err := buildImage(name,
-		`FROM busybox
+	buildImageSuccessfully(c, name, withDockerfile(`FROM busybox
 		RUN echo 'dockerio:x:1001:1001::/bin:/bin/false' >> /etc/passwd
-		USER dockerio`,
-		true)
-	c.Assert(err, checker.IsNil)
-
+		USER dockerio`))
 	dockerCmd(c, "run", "-d", "--name", "dockerioexec", name, "top")
 
 	out, _ := dockerCmd(c, "exec", "dockerioexec", "whoami")