Add convolve iteration algorithm with tests

[guillaume-chevalier]

Bonjour,

I added the convolve iteration algorithm with tests: a simple way to do convolutions on lists.

• If creating a new file :

  • added links to it in the README files ?
  • included tests with it ?
  • added description (overview of algorithm, time and space compleixty, and possible edge case) in docstrings ?

• if done some changes :

  • wrote short description in the PR explaining what the changes do ?
  • Fixes #[issue number] if related to any issue

• other

[guillaume-chevalier]

Note: the test test_plus_one_v3 fails and was already failing before opening this PR, everything else works:

py36 runtests: commands[0] | python3 -m unittest discover tests
.................E...............................................................................................................................................................................................................................
======================================================================
ERROR: test_plus_one_v3 (test_array.TestPlusOne)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/travis/build/keon/algorithms/tests/test_array.py", line 252, in test_plus_one_v3
    self.assertListEqual(plus_one_v3([0]), [1])
  File "/home/travis/build/keon/algorithms/algorithms/arrays/plus_one.py", line 45, in plus_one_v3
    num_arr[idx] = (num_arr[idx] + 1) % 10
TypeError: list indices must be integers, not tuple
----------------------------------------------------------------------
Ran 241 tests in 0.433s
FAILED (errors=1)
ERROR: InvocationError for command '/home/travis/build/keon/algorithms/.tox/py36/bin/python3 -m unittest discover tests' (exited with code 1)
___________________________________ summary ____________________________________
ERROR:   py36: commands failed
The command "tox -e $TOX_ENV" exited with 1.
0.45s$ pip3 uninstall -y algorithms
Uninstalling algorithms-0.1.0:
  Successfully uninstalled algorithms-0.1.0

[keon]

thanks! I left some comments

[guillaume-chevalier]

Thanks for the review and for your time!

[guillaume-chevalier]

I made the changes.

[guillaume-chevalier]

@keon I finally decided to make the requested changes.