Compile and link core tests with libuv
diff --git a/grpc.gemspec b/grpc.gemspec
index ae4c392..a290751 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -359,6 +359,7 @@
s.files += %w( src/core/lib/iomgr/combiner.c )
s.files += %w( src/core/lib/iomgr/endpoint.c )
s.files += %w( src/core/lib/iomgr/endpoint_pair_posix.c )
+ s.files += %w( src/core/lib/iomgr/endpoint_pair_uv.c )
s.files += %w( src/core/lib/iomgr/endpoint_pair_windows.c )
s.files += %w( src/core/lib/iomgr/error.c )
s.files += %w( src/core/lib/iomgr/ev_epoll_linux.c )