cherry-pick BuildLogMsg

ofborg/src/message/buildlogmsg.rs

@@ -0,0 +1,9 @@
+use ofborg::message::{Pr,Repo};
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct BuildLogMsg {
+    pub line_number: u64,
+    pub output: String,
+    pub identity: String,
+    pub system: String,
+}

ofborg/src/message/mod.rs

@@ -3,6 +3,6 @@ pub mod buildjob;
 pub mod buildresult;
 pub mod massrebuildjob;
 pub mod plasticheartbeat;
-
+pub mod buildlogmsg;
 
 pub use self::common::{Pr,Repo};