Add update_check_run endpoint

Author: Keno

README.md

@@ -222,6 +222,7 @@ GitHub.jl implements a bunch of methods that make REST requests to GitHub's API.
 | method                                   | return type                        | documentation                                                                                                                                                                                               |
 |------------------------------------------|------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `create_check_run(repo; params=...)`     | `CheckRun`                         | [Create a new check run](https://developer.github.com/v3/checks/runs/#create-a-check-run)   |
+| `update_check_run(repo, id::Int; params=...)`     | `CheckRun`                | [Update the check run with the given `id`](https://developer.github.com/v3/checks/runs/#update-a-check-run)   |
 
 
 #### Miscellaneous

src/GitHub.jl

@@ -257,7 +257,8 @@ export # installations.jl
 
 export # runs.jl
        Checks,
-       create_check_run
+       create_check_run,
+       update_check_run
 
 #######
 # Git #

src/apps/checks/runs.jl

@@ -44,7 +44,7 @@ struct CheckRun <: GitHubType
     started_at::Nullable{DateTime}
     completed_at::Nullable{DateTime}
     app::Nullable{App}
-    pull_requests::Vector{PullRequest}
+    pull_requests::Nullable{Vector{PullRequest}}
 end
 CheckRun(data::Dict) = json2github(CheckRun, data)
 namefield(cr::CheckRun) = cr.id
@@ -54,3 +54,9 @@ namefield(cr::CheckRun) = cr.id
     result = gh_post_json(api, "/repos/$(name(repo))/check-runs"; headers=headers, kwargs...)
     return CheckRun(result)
 end
+
+@api_default function update_check_run(api::GitHubAPI, repo::Repo, id::Int; headers = Dict(), kwargs...)
+    headers["Accept"] = "application/vnd.github.antiope-preview+json"
+    result = gh_patch_json(api, "/repos/$(name(repo))/check-runs/$(id)"; headers=headers, kwargs...)
+    return CheckRun(result)
+end