Return a DataFrame from HPAT Jited function #173

@hpat.jit
def test2():
    t0 = time.time()
    df = pandas.read_csv('random.csv', names=['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J'], dtype={'A' : 'float', 'B' : 'float', 'C' : 'float', 'D' : 'float', 'E' : 'float', 'F' : 'float', 'G' : 'float', 'H': 'float', 'I': 'str', 'J': 'str'})
    t_readcsv = time.time() - t0
    print('t_readcsv = ', t_readcsv)

    t0 = time.time()
    res = ( df.A.mean(), df.A.max(), df.A.min() , df.B.mean(), df.B.max(), df.B.min())
    t_calc = time.time() - t0
    print('t_calc = ', t_calc)

    return df

df = test2()

time mpiexec -n 2 python test_hpat3.py
real    0m33.568s

time mpiexec -n 8 python test_hpat3.py
real    0m32.557s

time mpiexec -n 16 python test_hpat3.py
real    0m37.037s

time mpiexec -n 32 python test_hpat3.py
real    0m48.858s

time mpiexec -n 44 python test_hpat3.py

===================================================================================
=   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
=   PID 68909 RUNNING AT CR3PPM-SER010
=   EXIT CODE: 9
=   CLEANING UP REMAINING PROCESSES
=   YOU CAN IGNORE THE BELOW CLEANUP MESSAGES
===================================================================================
YOUR APPLICATION TERMINATED WITH THE EXIT STRING: Killed (signal 9)
This typically refers to a problem with your application.
Please see the FAQ page for debugging suggestions

real    0m38.648s
user    22m1.044s
sys     4m20.828s