Switch to spf13/cobra from urfave/cli

There's A LOT happening in this commit, so here's an outline:

First off, urfave/cli has been removed in favour of spf13/cobra. With
this, comes changes to the formatting as well as the help page for
Kompose.

Upon converting, I noticed a CLI flag was NOT appearing for OpenShift.
Specifically, --deploymentconfig. This has been added with a note
that says it is OpenShift only.

Exit codes have been fixed. If the conversion / down / up fails for
any reason, Kompose will exit with Code 1.

--verbose as well as --suppress-warnings can now be set at the
same time.

app_test.go in the cli directory has been moved to pkg/transformer
to better reflect the testing coverage.

version.go has been removed and converted to it's own CLI command in
conjuction with (most) Go software. A new CLI command has been
created. kompose version

--dab isn't a conventional way for short-form CLI paramters. This
has been shortened to -b for bundle.

CLI flags consisting of only two/three letters have been removed due to
it being unconventional for CLI. For example, --dc was removed in preference
for --deploymentconfig

--replicas has been added as an option when using kompose down or
kompose up. This has been added as previously in app.go the
replica amount was hard-coded as 1.

Differentiating names have been used for flags. For example,
persistent flags use the name Global (ex. GlobalOut). Command-specific
flags have their own names (ex. UpOpt).

Closes #239 #253

main.go

@@ -16,37 +16,8 @@ limitations under the License.
 
 package main
 
-import (
-	"os"
-
-	"github.com/kubernetes-incubator/kompose/cli/command"
-	"github.com/kubernetes-incubator/kompose/version"
-	"github.com/urfave/cli"
-)
+import "github.com/kubernetes-incubator/kompose/cmd"
 
 func main() {
-	app := cli.NewApp()
-	app.Name = "kompose"
-	app.Usage = "A tool helping Docker Compose users move to Kubernetes."
-	app.Version = version.VERSION + " (" + version.GITCOMMIT + ")"
-	app.Author = "Kompose Contributors"
-	app.Email = "https://github.com/kubernetes-incubator/kompose"
-	app.EnableBashCompletion = true
-	app.Before = command.BeforeApp
-	app.Flags = append(command.CommonFlags())
-	app.Commands = []cli.Command{
-		// NOTE: Always add this in first, because this dummy command will be removed later
-		// in  command.BeforeApp function and provider specific command will be added
-		command.ConvertCommandDummy(),
-		// command.ConvertKubernetesCommand or command.ConvertOpenShiftCommand
-		// is added depending on provider mentioned.
-
-		command.UpCommand(),
-		command.DownCommand(),
-		// TODO: enable these commands and update docs once we fix them
-		//command.PsCommand(),
-		//command.ScaleCommand(),
-	}
-
-	app.Run(os.Args)
+	cmd.Execute()
 }