Clean vendor dependencies

vendor/github.com/cenkalti/backoff/context.go

@@ -1,63 +0,0 @@
-package backoff
-
-import (
-	"context"
-	"time"
-)
-
-// BackOffContext is a backoff policy that stops retrying after the context
-// is canceled.
-type BackOffContext interface {
-	BackOff
-	Context() context.Context
-}
-
-type backOffContext struct {
-	BackOff
-	ctx context.Context
-}
-
-// WithContext returns a BackOffContext with context ctx
-//
-// ctx must not be nil
-func WithContext(b BackOff, ctx context.Context) BackOffContext {
-	if ctx == nil {
-		panic("nil context")
-	}
-
-	if b, ok := b.(*backOffContext); ok {
-		return &backOffContext{
-			BackOff: b.BackOff,
-			ctx:     ctx,
-		}
-	}
-
-	return &backOffContext{
-		BackOff: b,
-		ctx:     ctx,
-	}
-}
-
-func ensureContext(b BackOff) BackOffContext {
-	if cb, ok := b.(BackOffContext); ok {
-		return cb
-	}
-	return WithContext(b, context.Background())
-}
-
-func (b *backOffContext) Context() context.Context {
-	return b.ctx
-}
-
-func (b *backOffContext) NextBackOff() time.Duration {
-	select {
-	case <-b.ctx.Done():
-		return Stop
-	default:
-	}
-	next := b.BackOff.NextBackOff()
-	if deadline, ok := b.ctx.Deadline(); ok && deadline.Sub(time.Now()) < next {
-		return Stop
-	}
-	return next
-}