feat(deploy): Simplifies deploy overview (#508)

This simplifies the deploy overview, to only show 3 version fields:
- CURRENT DEPLOYMENT
- CURRENT ENV
- NEW DEPLOYMENT

It also fixes a few errors around version detection

Reviewed-on: toolshed/abra#508
Co-authored-by: p4u1 <p4u1_f4u1@riseup.net>
Co-committed-by: p4u1 <p4u1_f4u1@riseup.net>

cli/app/upgrade.go

@@ -43,7 +43,8 @@ beforehand. See "abra app backup" for more.`,
 	ValidArgsFunction: func(
 		cmd *cobra.Command,
 		args []string,
-		toComplete string) ([]string, cobra.ShellCompDirective) {
+		toComplete string,
+	) ([]string, cobra.ShellCompDirective) {
 		switch l := len(args); l {
 		case 0:
 			return autocomplete.AppNameComplete()
@@ -206,23 +207,21 @@ beforehand. See "abra app backup" for more.`,
 			return
 		}
 
-		chaosVersion := config.CHAOS_DEFAULT
-		if deployMeta.IsChaos {
-			chaosVersion = deployMeta.ChaosVersion
-
-			if deployMeta.ChaosVersion == "" {
-				chaosVersion = config.UNKNOWN_DEFAULT
-			}
+		if upgradeReleaseNotes != "" && chosenUpgrade != "" {
+			fmt.Print(upgradeReleaseNotes)
+		} else {
+			upgradeWarnMessages = append(
+				upgradeWarnMessages,
+				fmt.Sprintf("no release notes available for %s", chosenUpgrade),
+			)
 		}
 
-		if err := internal.NewVersionOverview(
+		if err := internal.DeployOverview(
 			app,
-			upgradeWarnMessages,
-			"upgrade",
 			deployMeta.Version,
-			chaosVersion,
 			chosenUpgrade,
 			upgradeReleaseNotes,
+			upgradeWarnMessages,
 		); err != nil {
 			log.Fatal(err)
 		}
@@ -365,7 +364,7 @@ func validateUpgradeVersionArg(
 
 	parsedDeployedVersion, err := tagcmp.Parse(deployMeta.Version)
 	if err != nil {
-		return err
+		return fmt.Errorf("'%s' is not a known version", deployMeta.Version)
 	}
 
 	if parsedSpecificVersion.IsLessThan(parsedDeployedVersion) &&
@@ -397,9 +396,7 @@ func ensureDeployed(cl *dockerClient.Client, app app.App) (stack.DeployMeta, err
 	return deployMeta, nil
 }
 
-var (
-	showReleaseNotes bool
-)
+var showReleaseNotes bool
 
 func init() {
 	AppUpgradeCommand.Flags().BoolVarP(