Implement categories support

examples/bffh.dhall

@@ -43,6 +43,7 @@
     },
     Another = 
     { wiki = "test_another"
+    , category = "test"
     , disclose = "lab.test.read"
     , manage = "lab.test.admin"
     , name = "Another"

src/api/machines.rs

@@ -194,6 +194,9 @@ async fn fill_machine_builder(
     if let Some(ref wiki) = machine.desc.wiki {
         builder.set_wiki(wiki);
     }
+    if let Some(ref category) = machine.desc.category {
+        builder.set_category(category);
+    }
     builder.set_urn(&format!("urn:fabaccess:resource:{}", id.as_ref()));
 
     let machineapi = Machine::new(user.clone(), perms, machine.clone());

src/config.rs

@@ -97,6 +97,7 @@ impl Default for Config {
             name: "Testmachine".to_string(),
             description: Some("A test machine".to_string()),
             wiki: None,
+            category: None,
             privs: PrivilegesBuf {
                 disclose: PermissionBuf::from_string("lab.test.read".to_string()),
                 read: PermissionBuf::from_string("lab.test.read".to_string()),

src/machine.rs

@@ -368,6 +368,9 @@ pub struct MachineDescription {
     #[serde(default, skip_serializing_if = "Option::is_none", deserialize_with = "deser_option")]
     pub wiki: Option<String>,
 
+    #[serde(default, skip_serializing_if = "Option::is_none", deserialize_with = "deser_option")]
+    pub category: Option<String>,
+
     /// The permission required
     #[serde(flatten)]
     pub privs: access::PrivilegesBuf,