message: Fix signed/unsigned mismatches.
diff: #include <sstream>
  #include <numeric>
  +#pragma GCC diagnostic push
  +#pragma GCC diagnostic ignored "-Wsign-compare"
  #include <boost/test/unit_test.hpp>
  +#pragma GCC diagnostic pop
  #include <boost/iostreams/concepts.hpp>
  #include <boost/iostreams/stream_buffer.hpp>
  #include <boost/algorithm/string/predicate.hpp>
  @@ -118,7 +121,7 @@ void CallFunction(tester& test, T ac, const vector<char>& data, const vector<acc
  auto pl = vector<permission_level>{{scope[0], config::active_name}};
  if (scope.size() > 1)
  - for (int i=1; i < scope.size(); i++)
  + for (unsigned int i=1; i < scope.size(); i++)
  pl.push_back({scope[i], config::active_name});
  action act(pl, ac);
  @@ -309,7 +312,7 @@ BOOST_FIXTURE_TEST_CASE(action_tests, tester) { try {
  auto tm = test_api_action<TEST_METHOD("test_action", "require_auth")>{};
  auto pl = a3a4;
  if (a3a4_scope.size() > 1)
  - for (int i=1; i < a3a4_scope.size(); i++)
  + for (unsigned int i=1; i < a3a4_scope.size(); i++)
  pl.push_back({a3a4_scope[i], config::active_name});
  action act(pl, tm);
  @@ -612,7 +615,7 @@ BOOST_FIXTURE_TEST_CASE(chain_tests, tester) { try {
  produce_blocks(100);
  auto& gpo = control->get_global_properties();
  std::vector<account_name> prods(gpo.active_producers.producers.size());
  - for ( int i=0; i < gpo.active_producers.producers.size(); i++ ) {
  + for ( unsigned int i=0; i < gpo.active_producers.producers.size(); i++ ) {
  prods[i] = gpo.active_producers.producers[i].producer_name;
  }
  