Decode error AND Add catalan language to LANGUAGE_MAPPING

[dmiro]

1. Add catalan language to LANGUAGE_MAPPING.
I previously I added the file with stop words in project "stop-words"

2. Decode error

stop_words = [line.strip().decode('utf-8')
             for line in language_file.readlines()]

Strip() return a copy of the string with leading and trailing whitespace characters removed.
But if the string contains non-ascii characters, Strip() causes a UnicodeDecodeError error
(eg UnicodeDecodeError: 'utf8' codec can not decode byte 0xc3 in position 34: unexpected end of data).

The workaround is to reorder the call:

stop_words = [line.decode('utf-8').strip()
             for line in language_file.readlines()]

[Alir3z4]

@dmiro good job.
I've merged both of the patches for repos.

I'll update the sub-module for this repo and release soon.

Thanks ;)