Fix move compilation errors in `find_and_track_build_and_update_status`

I had a bunch of compilation errors in this function because I wasn't
borrowing correctly. Fix the errors with borrows by reference, and
copying strings.

Here are the errors for reference:

    error[E0373]: closure may outlive the current function, but it borrows `job`, which is owned by the current function
      --> src/jenkins.rs:89:27
       |
    89 |             thread::spawn(|| {
       |                           ^^ may outlive borrowed value `job`
    ...
    94 |                     job.result.commit_status(),
       |                     --- `job` is borrowed here
       |
    help: to force the closure to take ownership of `job` (and any other referenced variables), use the `move` keyword
       |
    89 |             thread::spawn(move || {
       |                           ^^^^^^^

    error[E0373]: closure may outlive the current function, but it borrows `job_url`, which is owned by the current function
      --> src/jenkins.rs:89:27
       |
    89 |             thread::spawn(|| {
       |                           ^^ may outlive borrowed value `job_url`
    ...
    96 |                     job_url.clone(),
       |                     ------- `job_url` is borrowed here
       |
    help: to force the closure to take ownership of `job_url` (and any other referenced variables), use the `move` keyword
       |
    89 |             thread::spawn(move || {
       |                           ^^^^^^^

    error[E0382]: use of moved value: `commit_ref`
      --> src/jenkins.rs:88:32
       |
    88 |         if job_for_commit(job, commit_ref) {
       |                                ^^^^^^^^^^ value moved here in previous iteration of loop
       |
       = note: move occurs because `commit_ref` has type `pull_request::CommitRef`, which does not implement the `Copy` trait

    error[E0382]: capture of moved value: `commit_ref`
      --> src/jenkins.rs:93:21
       |
    88 |         if job_for_commit(job, commit_ref) {
       |                                ---------- value moved here
    ...
    93 |                     commit_ref,
       |                     ^^^^^^^^^^ value captured here after move
       |
       = note: move occurs because `commit_ref` has type `pull_request::CommitRef`, which does not implement the `Copy` trait

    error[E0382]: capture of moved value: `job`
      --> src/jenkins.rs:89:27
       |
    88 |         if job_for_commit(job, commit_ref) {
       |                           --- value moved here
    89 |             thread::spawn(|| {
       |                           ^^ value captured here after move
       |
       = note: move occurs because `job` has type `jenkins::Job`, which does not implement the `Copy` trait

    error[E0382]: capture of moved value: `job_url`
      --> src/jenkins.rs:89:27
       |
    85 |         let job = request_job(job_url);
       |                               ------- value moved here
    ...
    89 |             thread::spawn(|| {
       |                           ^^ value captured here after move
       |
       = note: move occurs because `job_url` has type `std::string::String`, which does not implement the `Copy` trait

1 files changed, 1 insertions, 1 deletions

diff --git a/src/af83.rs b/src/af83.rs
index bc8876c..1547700 100644
--- a/src/af83.rs
+++ b/src/af83.rs
@@ -1,6 +1,6 @@
 use pull_request::CommitRef;
 
-pub fn job_name(commit_ref: CommitRef) -> String {
+pub fn job_name(commit_ref: &CommitRef) -> String {
     let (sha, _) = commit_ref.sha.split_at(5);
 
     format!("{}-{}", commit_ref.branch, sha)