Wrong 'editor' var results in Blockly not working

[JakubLenski]

python-main.js contains two variables named editor, one all uppercase and the other lowercase. The use of the wrong EDITOR var (line 441 & 453) results in the variable not having the specified methods therefore returning an error as 'undefined'.

[microbit-carlos]

Thanks for the report @JakubLenski.
This is related to #103 specifically #103 (comment).