client, server: new CIDRs must be hostname-compatible

towards the goal of supporting #82

shared/src/prompts.rs

@@ -39,7 +39,7 @@ pub fn add_cidr(cidrs: &[Cidr], request: &AddCidrOpts) -> Result<Option<CidrCont
     };
 
     let cidr_request = CidrContents {
-        name,
+        name: name.to_string(),
         cidr,
         parent: Some(parent_cidr.id),
     };

shared/src/types.rs

@@ -322,7 +322,7 @@ pub struct AddPeerOpts {
 pub struct AddCidrOpts {
     /// The CIDR name (eg. "engineers")
     #[structopt(long)]
-    pub name: Option<String>,
+    pub name: Option<Hostname>,
 
     /// The CIDR network (eg. "10.42.5.0/24")
     #[structopt(long)]
@@ -581,7 +581,7 @@ impl FromStr for Hostname {
         if Self::is_valid(name) {
             Ok(Self(name.to_string()))
         } else {
-            Err("invalid hostname")
+            Err("invalid hostname string (only alphanumeric with dashes)")
         }
     }
 }