Merge branch '1.0.x'

Author: marcingrzejszczak

micrometer-tracing/src/main/java/io/micrometer/tracing/handler/TracingObservationHandler.java

@@ -183,7 +183,7 @@ class TracingContext {
 
         private Span span;
 
-        Map<Thread, CurrentTraceContext.Scope> scopes = new ConcurrentHashMap<>();
+        private Map<Thread, CurrentTraceContext.Scope> scopes = new ConcurrentHashMap<>();
 
         /**
          * Returns the span.