Include fix which was causing build errors do to differences in (#10)

Vizerai · web-flow · commit eaf0505f520a · 2018-01-04T11:16:27.000-08:00
transitive includes between compilers.
diff --git a/opencensus/stats/internal/measure_registry_impl.h b/opencensus/stats/internal/measure_registry_impl.h
@@ -16,7 +16,9 @@
 #define OPENCENSUS_STATS_INTERNAL_MEASURE_REGISTRY_IMPL_H_
 
 #include <cstdint>
+#include <string>
 #include <unordered_map>
+#include <vector>
 
 #include "absl/strings/string_view.h"
 #include "absl/synchronization/mutex.h"
