README tutorial is broken for channel coding

[londumas]

README tutorial is broken

Please replace trellis = cc.Trellis(M, generator_matrix) # Trellis structure by trellis = cc.Trellis(np.array([M]), generator_matrix) # Trellis structure, or so it seems.

AttributeError                            Traceback (most recent call last)
<ipython-input-5-d8ad681885c7> in <module>
      3 m = np.array([L-1]) # number of delay elements
      4 generator_matrix = np.array([[0o171, 0o133]]) # generator branches
----> 5 trellis = cc.Trellis([M], generator_matrix) # Trellis structure

<ME>/CommPy/commpy/channelcoding/convcode.py in __init__(self, memory, g_matrix, feedback, code_type, polynomial_format)
    120         self.code_type = code_type
    121 
--> 122         self.total_memory = memory.sum()
    123         self.number_states = pow(2, self.total_memory)
    124         self.number_inputs = pow(2, self.k)

AttributeError: 'list' object has no attribute 'sum'

import numpy as np
import commpy.channelcoding.convcode as cc
import commpy.modulation as modulation

def BER_calc(a, b):
    num_ber = np.sum(np.abs(a - b))
    ber = np.mean(np.abs(a - b))
    return int(num_ber), ber

N = 100000 #number of symbols per the frame
message_bits = np.random.randint(0, 2, N) # message

M = 4 # modulation order (QPSK)
k = np.log2(M) #number of bit per modulation symbol
modem = modulation.PSKModem(M) # M-PSK modem initialization 
trellis = cc.Trellis(M, generator_matrix) # Trellis structure

rate = 1/2 # code rate
L = 7 # constraint length
m = np.array([L-1]) # number of delay elements
generator_matrix = np.array([[0o171, 0o133]]) # generator branches
trellis = cc.Trellis(M, generator_matrix) # Trellis structure

[londumas]

Fixed in PR https://github.com/veeresht/CommPy/pull/92