Use mapbox-gl-test-suite

Currently hard-failing on:

```
WARNING: ThreadSanitizer: data race (pid=15183)
  Write of size 8 at 0x7d28000a3e58 by thread T10:
    #0 mbgl::Sprite::parseJSON(std::shared_ptr<mbgl::Sprite>&) ??:0 (exe+0x000000213858)
    #1 uv::work<std::shared_ptr<mbgl::Sprite> >::do_work(uv_work_s*) ??:0 (exe+0x0000002150de)
    #2 worker src/unix/threadpool.c:0 (exe+0x0000002e98aa)
  Previous read of size 8 at 0x7d28000a3e58 by main thread:
    #0 mbgl::Sprite::complete(std::shared_ptr<mbgl::Sprite>&) ??:0 (exe+0x000000211f32)
    #1 uv::work<std::shared_ptr<mbgl::Sprite> >::after_work(uv_work_s*, int) ??:0 (exe+0x000000215129)
    #2 uv__work_done ??:0 (exe+0x0000002e95e8)
    #3 HeadlessTest_render_Test::TestBody() ??:0 (exe+0x00000013087f)
    #4 void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) ??:0 (exe+0x0000001931a4)
    #5 testing::Test::Run() ??:0 (exe+0x000000158d15)
    #6 testing::TestInfo::Run() ??:0 (exe+0x00000015af00)
    #7 testing::TestCase::Run() ??:0 (exe+0x00000015bc87)
    #8 testing::internal::UnitTestImpl::RunAllTests() ??:0 (exe+0x00000016ec20)
    #9 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) ??:0 (exe+0x0000001945d4)
    #10 testing::UnitTest::Run() ??:0 (exe+0x00000016e239)
    #11 main ??:0 (exe+0x00000012d07f)
  Location is heap block of size 160 at 0x7d28000a3de0 allocated by main thread:
    #0 operator new /home/users/aadgrand/LLVM/releases/ubuntu/final/llvm.src/projects/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc:560 (exe+0x0000000ce9b9)
    #1 _ZNSt14__shared_countILN9__gnu_cxx12_Lock_policyE2EEC2IN4mbgl6SpriteESaIS5_EJRNS4_3MapEfEEESt19_Sp_make_shared_tagPT_RKT0_DpOT1_ ??:0 (exe+0x0000001ab586)
    #2 _ZNSt12__shared_ptrIN4mbgl6SpriteELN9__gnu_cxx12_Lock_policyE2EEC2ISaIS1_EJRNS0_3MapEfEEESt19_Sp_make_shared_tagRKT_DpOT0_ ??:0 (exe+0x0000001ab3d8)
    #3 mbgl::Map::prepare() ??:0 (exe+0x0000001a3c0a)
    #4 mbgl::Map::run() ??:0 (exe+0x0000001a39d2)
    #5 HeadlessTest_render_Test::TestBody() ??:0 (exe+0x00000013087f)
    #6 void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) ??:0 (exe+0x0000001931a4)
    #7 testing::Test::Run() ??:0 (exe+0x000000158d15)
    #8 testing::TestInfo::Run() ??:0 (exe+0x00000015af00)
    #9 testing::TestCase::Run() ??:0 (exe+0x00000015bc87)
    #10 testing::internal::UnitTestImpl::RunAllTests() ??:0 (exe+0x00000016ec20)
    #11 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) ??:0 (exe+0x0000001945d4)
    #12 testing::UnitTest::Run() ??:0 (exe+0x00000016e239)
    #13 main ??:0 (exe+0x00000012d07f)
  Thread T10 (tid=15194, running) created by main thread at:
    #0 pthread_create /home/users/aadgrand/LLVM/releases/ubuntu/final/llvm.src/projects/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc:877 (exe+0x0000000d266b)
    #1 uv_thread_create ??:0 (exe+0x0000002e0432)
    #2 uv_once ??:0 (exe+0x0000002e8f45)
    #3 mbgl::TileData::reparse() ??:0 (exe+0x00000021775c)
    #4 std::_Function_handler<void (mbgl::platform::Response*), mbgl::TileData::request()::$_1>::_M_invoke(std::_Any_data const&, mbgl::platform::Response*) ../../src/map/tile_data.cpp:0 (exe+0x000000217c24)
    #5 mbgl::platform::Request::complete(uv_async_s*) ??:0 (exe+0x0000001a0f4d)
    #6 uv__async_event src/unix/async.c:0 (exe+0x0000002e08c3)
    #7 HeadlessTest_render_Test::TestBody() ??:0 (exe+0x00000013087f)
    #8 void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) ??:0 (exe+0x0000001931a4)
    #9 testing::Test::Run() ??:0 (exe+0x000000158d15)
    #10 testing::TestInfo::Run() ??:0 (exe+0x00000015af00)
    #11 testing::TestCase::Run() ??:0 (exe+0x00000015bc87)
    #12 testing::internal::UnitTestImpl::RunAllTests() ??:0 (exe+0x00000016ec20)
    #13 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) ??:0 (exe+0x0000001945d4)
    #14 testing::UnitTest::Run() ??:0 (exe+0x00000016e239)
    #15 main ??:0 (exe+0x00000012d07f)
SUMMARY: ThreadSanitizer: data race ??:0 mbgl::Sprite::parseJSON(std::shared_ptr<mbgl::Sprite>&)
```