Add NLP unittests

Add NLP unittests

root@localhost:~# /usr/bin/nlp_unittests
[==========] Running 4 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 4 tests from NlpServiceTest
[ RUN      ] NlpServiceTest.utc_nlp_service_tokenize_p
token: 'I'
token: 'am'
token: 'a'
token: 'boy'
word_tokenize process done
[       OK ] NlpServiceTest.utc_nlp_service_tokenize_p (5015 ms)
[ RUN      ] NlpServiceTest.utc_nlp_service_language_detect_p
Detected language: en
[       OK ] NlpServiceTest.utc_nlp_service_language_detect_p (79 ms)
[ RUN      ] NlpServiceTest.utc_nlp_service_pos_tag_p
tag : NNP
tag : NNP
[       OK ] NlpServiceTest.utc_nlp_service_pos_tag_p (2066 ms)
[ RUN      ] NlpServiceTest.utc_nlp_service_ne_chunk_p
tag: PRP
token: We
tag: VBD
token: saw
tag: DT
token: the
tag: JJ
token: yellow
tag: NN
token: dog
ne_chunk process done
[       OK ] NlpServiceTest.utc_nlp_service_ne_chunk_p (2138 ms)
[----------] 4 tests from NlpServiceTest (9299 ms total)

[----------] Global test environment tear-down
[==========] 4 tests from 1 test case ran. (9300 ms total)
[  PASSED  ] 4 tests.

Change-Id: I8f82875e4ea0c9351a8335976af4967a7daf1673
Signed-off-by: Jihoon Kim <jihoon48.kim@samsung.com>