updog: print space between variant and version rather than hyphen

Variant names can include versions (e.g. aws-k8s-1.15) and seeing that combined
with the update version using a hyphen can be confusing.  For example, in
aws-k8s-1.15-0.3.0, it's unclear what each version applies to.  This change
uses a space instead, to visually separate the two components.

sources/updater/updog/src/main.rs

@@ -422,7 +422,7 @@ fn parse_args(args: std::env::Args) -> Arguments {
 }
 
 fn fmt_full_version(update: &Update) -> String {
-    format!("{}-{}", update.variant, update.version)
+    format!("{} {}", update.variant, update.version)
 }
 
 fn output<T: Serialize>(json: bool, object: T, string: &str) -> Result<()> {
@@ -532,7 +532,7 @@ fn main_inner() -> Result<()> {
                     output(
                         arguments.json,
                         &u,
-                        &format!("Update applied: {}-{}", u.variant, u.version),
+                        &format!("Update applied: {}", fmt_full_version(&u)),
                     )?;
                 } else if let Some(wave) = u.jitter(config.seed) {
                     // return the jittered time of our wave in the update