v6.5.1

• Added separator argument to allow user to choose custom separator for load_dictionary
• Added load_bigram_dictionary and bigram dictionary frequency_bigramdictionary_en_243_342.txt
• Updated lookup_compound algorithm
• Added Levenshtein to compute edit distance
• Added save_pickle_stream and load_pickle_stream to save/load SymSpell data alongside other structure (contribution by marcoffee)