Add a function to add a new scope field from an existing Sentry scope (…

…#29)

This allows to use breadcrumbs while keeping the information tied to
non-default hubs by doing `log.With(zapsentry.NewScopeFromScope(hub.Scope()))`
(e.g. when using https: //docs.sentry.io/platforms/go/guides/http/).

core.go

@@ -18,14 +18,18 @@ const (
 	zapSentryScopeKey = "_zapsentry_scope_"
 )
 
-func NewScope() zapcore.Field {
+func NewScopeFromScope(scope *sentry.Scope) zapcore.Field {
 	f := zap.Skip()
-	f.Interface = sentry.NewScope()
+	f.Interface = scope
 	f.Key = zapSentryScopeKey
 
 	return f
 }
 
+func NewScope() zapcore.Field {
+	return NewScopeFromScope(sentry.NewScope())
+}
+
 func NewCore(cfg Configuration, factory SentryClientFactory) (zapcore.Core, error) {
 	client, err := factory()
 	if err != nil {