for loop without 'var' causes errors in some environments

[C451]

Hello,

Running your cool lib in electron and caught an error: for some reason node requires 'var' in the for loop:

https://github.com/Bitvested/ta.js/blob/main/index.js#L404

[Vultwo]

Hi, it should be fixed now.
Let me know if you encounter any other issues.