Merge pull request #9 from elenagr/master

ngrams and abbreviations dictionary
Summary of the tokenisation/stemming test.  Some useful quantities saved in the pickle
Merge pull request #10 from emsiepopples/master

Summary of the tokenisation/stemming test
Merge pull request #11 from elenagr/master

Word Files + ngrams and abbrevi in stemming_test.py
Merge pull request #12 from elenagr/master

Added ngrams and abbreviations as an option
Added seed option for the generation of the random sample