Use conlleval.txt to test NER

Refer to https://svn.spraakdata.gu.se/repos/richard/pub/ml2015_web/assignment3.html

When using conlleval.txt to test the results of named entity recognition, pay attention to the following points:
1. Only BIO format can be received.
2. The first column is characters, the second column is gold-standard annotation, and the third column is the predicted label. ;
3. Use spaces to separate each column of data.
4. Run the command perl conlleval.txt <test.py
5. An error occurred during runtime: unexpected number of features:1 (4)
Although most prompts on the Internet use the -d parameter, this problem still exists after I use it, and finally The solution is:
读取当前文件，重新写入新文件时用空格进行分隔。