Fixed readme's dfa.py link (#695)

Author: herpacsibenedek

README.md

@@ -72,7 +72,7 @@ If you want to uninstall algorithms, it is as simple as:
     - [move_zeros](algorithms/arrays/move_zeros.py)
     - [n_sum](algorithms/arrays/n_sum.py)
 - [automata](algorithms/automata)
-    - [DFA](algorithms/automata/DFA.py)
+    - [DFA](algorithms/automata/dfa.py)
 - [backtrack](algorithms/backtrack)
     - [general_solution.md](algorithms/backtrack/)
     - [add_operators](algorithms/backtrack/add_operators.py)
@@ -196,7 +196,7 @@ If you want to uninstall algorithms, it is as simple as:
     - [valid_sudoku](algorithms/map/valid_sudoku.py)
     - [word_pattern](algorithms/map/word_pattern.py)
     - [is_isomorphic](algorithms/map/is_isomorphic.py)
-    - [is_anagram](algorithms/map/is_anagram.py)    
+    - [is_anagram](algorithms/map/is_anagram.py)
 - [maths](algorithms/maths)
     - [power](algorithms/maths/power.py)
     - [base_conversion](algorithms/maths/base_conversion.py)
@@ -205,7 +205,7 @@ If you want to uninstall algorithms, it is as simple as:
     - [decimal_to_binary_ip](algorithms/maths/decimal_to_binary_ip.py)
     - [euler_totient](algorithms/maths/euler_totient.py)
     - [extended_gcd](algorithms/maths/extended_gcd.py)
-    - [factorial](algorithms/maths/factorial.py)    
+    - [factorial](algorithms/maths/factorial.py)
     - [gcd/lcm](algorithms/maths/gcd.py)
     - [generate_strobogrammtic](algorithms/maths/generate_strobogrammtic.py)
     - [is_strobogrammatic](algorithms/maths/is_strobogrammatic.py)