Preemptively support JSON 1.0 release

As [noted](JuliaIO/JSON.jl#374 (comment)),
the JSON 1.0 release is currently blocked on using Documenter due to the circular
dependency of needing Documenter to build docs. The usage of JSON.jl in Documenter.jl
is very vanilla, so this PR proposed "preemptive" support for JSON.jl 1.0 since
the usage of JSON in Documenter is known to not rely on any breaking changes proposed.

Author: quinnj

Project.toml

@@ -38,7 +38,7 @@ Downloads = "1.4"
 Git = "1"
 IOCapture = "0.2"
 InteractiveUtils = "1.6"
-JSON = "0.19, 0.20, 0.21"
+JSON = "0.19, 0.20, 0.21, 1"
 Logging = "1.6"
 Markdown = "1.6"
 MarkdownAST = "0.1.1"

src/deployconfig.jl

@@ -512,7 +512,7 @@ function post_github_status(type::S, deploydocs_repo::S, sha::S, subfolder = not
         else
             error("unsupported type: $type")
         end
-        push!(cmd.exec, "-d", sprint(JSON.print, json))
+        push!(cmd.exec, "-d", JSON.json(json))
         push!(cmd.exec, "https://api.github.com/repos/$(owner)/$(repo)/statuses/$(sha)")
         # Run the command (silently)
         io = IOBuffer()