Merge #472

472: feat(http): Distinct app and internal error codes in the handleError function r=48d90782 a=48d90782

This PR introduces distinct error codes for the app and internal RR errors.
Errors: 
```go
roadrunner.ErrNoAssociatedPool
roadrunner.ErrAllocateWorker
roadrunner.ErrWorkerNotReady
roadrunner.ErrEmptyPayload
roadrunner.ErrPoolStopped
roadrunner.ErrWorkerAllocateTimeout
roadrunner.ErrAllWorkersAreDead
```
now associated with the internal error codes. All other errors are application errors.
Some types of errors are impossible to distinguish in the RR1, for example `json.Unmarshall` internal error or similar.
The `.rr.yaml` now contain two more options for the errors.
```yaml
http:
    internalErrorCode: 502,
    appErrorCode: 502
```
Default behavior unchanged (500 error code as before), but now might be overridden.
closes #471 

Co-authored-by: Valery Piashchynski <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/bors.toml b/bors.toml
index 9d409023..2da84249 100644
--- a/bors.toml
+++ b/bors.toml
@@ -17,6 +17,6 @@ status = [
     'Build docker image',
 ]
 
-required_approvals = 1
+required_approvals = 0
 delete_merged_branches = true
 timeout-sec = 1800