added method models.word2vec.LineSentencePath

method to read an entire directory's files in the same style as
models.word2vec.LineSentence

initial attempt at test, including files. test just splits the
lee_background.cor file into two parts and puts them in a directory,
then makes sure they match the unsplit file as loaded by
word2vec.LineSentence

no longer sensitive to an input without a trailing os-specific slash

…into develop

in word2vec.py . Test updated as well

in models.word2vec . Tests also updated

had only 1 space before an inline comment, flagged by travis CI build

Removed LineSentencePath directory, created PathLineSentences
lee corpus duplicates were in LineSentencePath, was wasting space
made new small corpus to test PathLineSentences, put in directory
changed test to read both files manually, combine, and compare to
PathLineSentences (rather than having a separate single file to match
the entire contents of the PathLineSentences test_data directory

changed PathLineSentences to support a single file in addition to a
directory, raises a warning to use LineSentence when a single file is
given as a parameter. added corresponding test.

resolved test_word2vec.py manually

…into develop

…into develop