:alembic: fix string representation

test/src/unit-class_parser.cpp

diff --git a/test/src/unit-class_parser.cpp b/test/src/unit-class_parser.cpp
index c612daa..2df07d6 100644
--- a/test/src/unit-class_parser.cpp
+++ b/test/src/unit-class_parser.cpp
@@ -509,7 +509,7 @@
                 CHECK(parser_helper("\"€\"").get<json::string_t>() == "€");
                 CHECK(parser_helper("\"🎈\"").get<json::string_t>() == "🎈");
 
-                CHECK(parser_helper("\"\\ud80c\\udc60\"").get<json::string_t>() == "\U00013060");
+                CHECK(parser_helper("\"\\ud80c\\udc60\"").get<json::string_t>() == "\xf0\x93\x81\xa0");
                 CHECK(parser_helper("\"\\ud83c\\udf1e\"").get<json::string_t>() == "🌞");
             }
         }

test/src/unit-regression1.cpp

diff --git a/test/src/unit-regression1.cpp b/test/src/unit-regression1.cpp
index f552005..df660dd 100644
--- a/test/src/unit-regression1.cpp
+++ b/test/src/unit-regression1.cpp
@@ -400,7 +400,7 @@
 
     SECTION("issue #146 - character following a surrogate pair is skipped")
     {
-        CHECK(json::parse("\"\\ud80c\\udc60abc\"").get<json::string_t>() == "\U00013060abc");
+        CHECK(json::parse("\"\\ud80c\\udc60abc\"").get<json::string_t>() == "\xf0\x93\x81\xa0\x61\x62\x63");
     }
 
     SECTION("issue #171 - Cannot index by key of type static constexpr const char*")