emulator: tests: rename rollback_test.cc to something more appropriate. (#20)

It now has tests well beyond the initial rollback tests, dealing with
all manner of bigtable mutations, so call it mutations_test.cc.

Author: marete

google/cloud/bigtable/emulator/CMakeLists.txt

@@ -59,8 +59,8 @@ if (BUILD_TESTING)
         drop_row_range_test.cc
         filter_test.cc
         filtered_map_test.cc
+        mutations_test.cc
         range_set_test.cc
-        rollback_test.cc
         server_test.cc
         table_test.cc)
     export_list_to_bazel("bigtable_emulator_unit_tests.bzl"

google/cloud/bigtable/emulator/bigtable_emulator_unit_tests.bzl

@@ -22,8 +22,8 @@ bigtable_emulator_unit_tests = [
     "drop_row_range_test.cc",
     "filter_test.cc",
     "filtered_map_test.cc",
+    "mutations_test.cc",
     "range_set_test.cc",
-    "rollback_test.cc",
     "server_test.cc",
     "table_test.cc",
 ]