Release 1.6

= Code refactored

+ Autodetection of vars in integral
+ Added simplifing rule for pow(x, 1)
+ Moved some functions to utils.py

Release 1.5

v1.5

Добавлено gui.py и обновлён integral.py

Release 1.4

+ Calculator now can take keyword arguments for variables

Release 1.1

+ Added simplifying rule for subtraction
+ Constants (Pi, Exp) added to variable list in simplyfing
= Bugfix for multiple var detection in derivative
= Changed symbol of negativation

Final(?) release

Release 1.0

+Unary operator parsing and composer support
+ Pretty input and output
= Code cleaning

Release 0.2

+ Simplifies expressions
+ Calculate simple non variable expressions
= Changed Constant value type to float

Initial release

v0.1

Initial release