travis: add osx target (testing osx only)
travis: add osx target (testing osx only)

skale-me/node-parquet,mvertes/node-parquet,mvertes/node-parquet,mvertes/node-parquet,skale-me/node-parquet,skale-me/node-parquet,skale-me/node-parquet,mvertes/node-parquet