`nimble test` fails locally on OSX and in CI
this makes it really awkward to write PRs

depending on what i do, i either get:
```
/Users/timothee/.nimble/pkgs/asynctools-#pr_fix_compilation/asynctools/asyncdns.nim(580, 16) Error: undeclared identifier: 'newAsyncNativeSocket'
```
or after i update `requires` via https://github.com/dom96/jester/pull/279, i get:

```
   Success: Execution finished
Getting http://localhost:5454
Connection refused
Async traceback:
  /Users/timothee/git_clone/nim/jester/tests/tester.nim(240)               tester
  /Users/timothee/git_clone/nim/jester/tests/tester.nim(61)                allTest
  /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1933) waitFor
  /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1625) poll
  /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1366) runOnce
  /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(206)  processPendingCallbacks
  /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncmacro.nim(28)      dialNimAsyncContinue
  /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncmacro.nim(131)     dialIter
  /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncfutures.nim(389)   read
  #[
    /Users/timothee/git_clone/nim/jester/tests/tester.nim(240)               tester
    /Users/timothee/git_clone/nim/jester/tests/tester.nim(61)                allTest
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1933) waitFor
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1625) poll
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1366) runOnce
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(206)  processPendingCallbacks
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncmacro.nim(28)      newConnectionNimAsyncContinue
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncmacro.nim(131)     newConnectionIter
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncfutures.nim(389)   read
  ]#
  #[
    /Users/timothee/git_clone/nim/jester/tests/tester.nim(240)               tester
    /Users/timothee/git_clone/nim/jester/tests/tester.nim(61)                allTest
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1933) waitFor
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1625) poll
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(1366) runOnce
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncdispatch.nim(206)  processPendingCallbacks
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncmacro.nim(28)      requestAuxNimAsyncContinue
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncmacro.nim(131)     requestAuxIter
    /Users/timothee/git_clone/nim/Nim_devel/lib/pure/asyncfutures.nim(389)   read
  ]#
...
```
