Resolve compilation errors if compiled with more stringent semantic checks.

Adding Travis test to build with strict warnings.
Fixing a warning in a test which used signed/unsigned integer comparison.

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/json/test_json.cc b/tests/json/test_json.cc
index 4465c76..828e603 100644
--- a/tests/json/test_json.cc
+++ b/tests/json/test_json.cc
@@ -347,7 +347,7 @@ void test_json_roundtrip() {
         test_case->input :
         test_case->expected;
 
-    for (int i = 0; i < strlen(test_case->input); i++) {
+    for (size_t i = 0; i < strlen(test_case->input); i++) {
       test_json_roundtrip_message(test_case->input, expected,
                                   serialize_handlers.get(), i);
     }