Work around flatbuffers flaky build
Work around flatbuffers flaky build

The flatbuffers build ocasionally fails with the following error:

/flatbuffers/flatbuffers-1.6.0/src/idl_parser.cpp
/mnt/source/flatbuffers/flatbuffers-1.6.0/samples/sample_binary.cpp:19:17:
error: 'MyGame' has not been declared
 using namespace MyGame::Sample;
                 ^
/mnt/source/flatbuffers/flatbuffers-1.6.0/samples/sample_binary.cpp:19:25:
error: 'Sample' is not a namespace-name
 using namespace MyGame::Sample;
                         ^
/mnt/source/flatbuffers/flatbuffers-1.6.0/samples/sample_binary.cpp:19:31:
error: expected namespace-name before ';' token
 using namespace MyGame::Sample;
                               ^
/mnt/source/flatbuffers/flatbuffers-1.6.0/samples/sample_binary.cpp: In
function 'int main(int, const char**)':
/mnt/source/flatbuffers/flatbuffers-1.6.0/samples/sample_binary.cpp:25:3:
error: 'flatbuffers' has not been declared
   flatbuffers::FlatBufferBuilder builder;
   ^
/mnt/source/flatbuffers/flatbuffers-1.6.0/samples/sample_binary.cpp:28:26:
error: 'builder' was not declared in this scope
   auto weapon_one_name = builder.CreateString("Sword");
                          ^
...

Disabling the BUILD_TESTS target removes the flakiness and makes the
compilation faster.

Change-Id: I57e95617ccfc2d7d63cc277ab2b858f28ccad44c
Reviewed-on: http://gerrit.cloudera.org:8080/12886
Reviewed-by: Tim Armstrong <2f8e34250f03a653da3dc27f7ec203eafdde80fc@cloudera.com>
Tested-by: Tim Armstrong <2f8e34250f03a653da3dc27f7ec203eafdde80fc@cloudera.com>

cloudera/native-toolchain,cloudera/native-toolchain,cloudera/native-toolchain,timarmstrong/native-toolchain