Add: Korean support

[BayMinimum]

Changes proposed in this pull request:

• Support for Korean language (Korean support #209)

Status

• READY
• HOLD
• WIP (Work-In-Progress)

How to verify this change

Run the test cases in tests/test_ko.py

[coveralls]

Pull Request Test Coverage Report for Build 542

• 63 of 68 (92.65%) changed or added relevant lines in 2 files are covered.
• 4 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.06%) to 90.038%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
num2words/lang_KO.py	62	67	92.54%

Files with Coverage Reduction	New Missed Lines	%
num2words/compat.py	4	100.0%

Totals
Change from base Build 537:	0.06%
Covered Lines:	2603
Relevant Lines:	2891

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 542

• 63 of 68 (92.65%) changed or added relevant lines in 2 files are covered.
• 4 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.06%) to 90.038%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
num2words/lang_KO.py	62	67	92.54%

Files with Coverage Reduction	New Missed Lines	%
num2words/compat.py	4	100.0%

Totals
Change from base Build 537:	0.06%
Covered Lines:	2603
Relevant Lines:	2891

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 544

• 63 of 68 (92.65%) changed or added relevant lines in 2 files are covered.
• 4 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.06%) to 90.038%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
num2words/lang_KO.py	62	67	92.54%

Files with Coverage Reduction	New Missed Lines	%
num2words/compat.py	4	100.0%

Totals
Change from base Build 537:	0.06%
Covered Lines:	2603
Relevant Lines:	2891

---

💛 - Coveralls

[erozqba]

@BayMinimum Thanks a lot for this contribution!
Could you please add a couple of tests to cover the missing lines here https://coveralls.io/builds/19610397/source?filename=num2words%2Flang_KO.py#L123