Update flake8 - #399

./exercises/anagram/anagram_test.py:70:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/beer-song/beer_song_test.py:69:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/binary/binary_test.py:47:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/binary-search/binary_search_test.py:40:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/bob/bob_test.py:122:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/clock/clock_test.py:160:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/etl/etl_test.py:52:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/gigasecond/gigasecond_test.py:48:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/grains/grains_test.py:35:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/leap/leap_test.py:22:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/meetup/meetup_test.py:65:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/nucleotide-count/nucleotide_count_test.py:40:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/ocr-numbers/example.py:9:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/ocr-numbers/ocr_test.py:105:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/perfect-numbers/perfect_numbers_test.py:41:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/phone-number/phone_number_test.py:39:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/pig-latin/pig_latin_test.py:52:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/point-mutations/point_mutations_test.py:34:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/poker/poker_test.py:104:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/prime-factors/prime_factors_test.py:40:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/pythagorean-triplet/example.py:39:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/rail-fence-cipher/rail_fence_cipher_test.py:33:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/raindrops/raindrops_test.py:55:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/rectangles/rectangles_count_test.py:71:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/robot-simulator/robot_simulator_test.py:72:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/roman-numerals/roman_numerals_test.py:32:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/run-length-encoding/run_length_test.py:36:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/say/say_test.py:68:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/scrabble-score/scrabble_score_test.py:28:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/sieve/sieve_test.py:32:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/space-age/space_age_test.py:50:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/triangle/triangle_test.py:66:1: E305 expected 2 blank lines after class or function definition, found 1
./exercises/word-count/word_count_test.py:87:1: E305 expected 2 blank lines after class or function definition, found 1