Add unicode letters generator

[elyezer]

This generator is a helper for the gen_utf8 function which will provide
the system supported list of unicode letters. This will avoid generating
unicode string with control characters and other non letters characters.

Also adds tests for the generator in order to ensure it is not
generating unwanted characters.

Closes #69

[coveralls]

Coverage decreased (-2.37%) to 97.33% when pulling 4178f1b on elyezer:unicode-letters into 3ca13df on omaciel:master.

[Ichimonji10]

chr_function = unichr  # pylint:disable=undefined-variable
range_function = xrange  # pylint:disable=undefined-variable

[Ichimonji10]

ACK pending comments

[coveralls]

Coverage increased (+0.0%) to 99.7% when pulling 204485f on elyezer:unicode-letters into 3ca13df on omaciel:master.

[Ichimonji10]

Unicode Standard Annex 44: Unicode Character Database, section 5.5.1 General Category Values explains the meaning of values such as "Lu" or "No".

[Ichimonji10]

Do you think the types of characters emitted by gen_utf8 is appropriate? Character categories such as "Decimal_Number" and "Currency_Symbol" are omitted. And, as Ke$ha demonstrates, those values actually are used in some weird places. We can make a judgment call and omit them. But in that case, the docstring for gen_utf8 should be updated appropriately.

[elyezer]

@Ichimonji10 I have updated the docstring. For testing purposes I think just the letters should suffice as probably we will get at least one UTF-8 glyph with 2 or more bytes. We can add more categories for sure, but I think is better to "stay safe", just using a multi-byte character will define if the system is capable of handling UTF-8 strings.

[coveralls]

Coverage increased (+0.0%) to 99.7% when pulling 8bbf290 on elyezer:unicode-letters into 3ca13df on omaciel:master.

[elyezer]

On my system I got a total of 48270 unicode letters. It is 73.66% of the maxunicode 65535.

[Ichimonji10]

ACK

[elyezer]

Have done some practical testing and here are the results:

With this changes:

$ py.test tests/foreman/api/test_user.py -k test_create
================================ test session starts ================================
platform darwin -- Python 2.7.6 -- py-1.4.26 -- pytest-2.6.4
collected 23 items

tests/foreman/api/test_user.py ...

====================== 20 tests deselected by '-ktest_create' =======================
===================== 3 passed, 20 deselected in 13.24 seconds ======================

$ py.test tests/foreman/api/test_user.py -k test_create
================================ test session starts ================================
platform darwin -- Python 2.7.6 -- py-1.4.26 -- pytest-2.6.4
collected 23 items

tests/foreman/api/test_user.py ...

====================== 20 tests deselected by '-ktest_create' =======================
====================== 3 passed, 20 deselected in 7.42 seconds ======================

$ py.test tests/foreman/api/test_user.py -k test_create
================================ test session starts ================================
platform darwin -- Python 2.7.6 -- py-1.4.26 -- pytest-2.6.4
collected 23 items

tests/foreman/api/test_user.py ...

====================== 20 tests deselected by '-ktest_create' =======================
====================== 3 passed, 20 deselected in 8.17 seconds ======================

$ py.test tests/foreman/api/test_user.py -k test_create
================================ test session starts ================================
platform darwin -- Python 2.7.6 -- py-1.4.26 -- pytest-2.6.4
collected 23 items

tests/foreman/api/test_user.py ...

====================== 20 tests deselected by '-ktest_create' =======================
===================== 3 passed, 20 deselected in 13.62 seconds ======================

 $ py.test tests/foreman/api/test_user.py -k test_create
================================ test session starts ================================
platform darwin -- Python 2.7.6 -- py-1.4.26 -- pytest-2.6.4
collected 23 items

tests/foreman/api/test_user.py ...

====================== 20 tests deselected by '-ktest_create' =======================
===================== 3 passed, 20 deselected in 28.24 seconds ======================

Without the changes

$ py.test tests/foreman/api/test_user.py -k test_create
================================ test session starts ================================
platform darwin -- Python 2.7.6 -- py-1.4.26 -- pytest-2.6.4
collected 23 items

tests/foreman/api/test_user.py FFF

===================================== FAILURES ======================================
2015-02-15 11:39:37 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"firstname":["is invalid"]},"full_messages":["First name is invalid"]}
}

2015-02-15 11:39:38 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"lastname":["is invalid"]},"full_messages":["Surname is invalid"]}
}

2015-02-15 11:39:39 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"login":["is invalid"]},"full_messages":["Username is invalid"]}
}

====================== 20 tests deselected by '-ktest_create' =======================
====================== 3 failed, 20 deselected in 4.93 seconds ======================

$ py.test tests/foreman/api/test_user.py -k test_create
================================ test session starts ================================
platform darwin -- Python 2.7.6 -- py-1.4.26 -- pytest-2.6.4
collected 23 items

tests/foreman/api/test_user.py FFF

===================================== FAILURES ======================================
2015-02-15 11:39:42 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"firstname":["is invalid"]},"full_messages":["First name is invalid"]}
}

2015-02-15 11:39:43 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"lastname":["is invalid"]},"full_messages":["Surname is invalid"]}
}

2015-02-15 11:39:44 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"login":["is invalid"]},"full_messages":["Username is invalid"]}
}

====================== 20 tests deselected by '-ktest_create' =======================
====================== 3 failed, 20 deselected in 3.81 seconds ======================

$ py.test tests/foreman/api/test_user.py -k test_create
================================ test session starts ================================
platform darwin -- Python 2.7.6 -- py-1.4.26 -- pytest-2.6.4
collected 23 items

tests/foreman/api/test_user.py FFF

===================================== FAILURES ======================================
2015-02-15 11:39:47 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"firstname":["is invalid"]},"full_messages":["First name is invalid"]}
}

2015-02-15 11:39:48 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"lastname":["is invalid"]},"full_messages":["Surname is invalid"]}
}

2015-02-15 11:39:49 - nailgun.client - WARNING - Received HTTP 422 response: {
  "error": {"id":null,"errors":{"login":["is invalid"]},"full_messages":["Username is invalid"]}
}

====================== 20 tests deselected by '-ktest_create' =======================
====================== 3 failed, 20 deselected in 3.47 seconds ======================

For this test I commented out all non UTF-8 test data and I removed most of the failures output and left just the invalid messages. Also I ran more than once to get other random values.

[omaciel]

ACK