fix: update decaffeinate-parser dependency to keep coffee-lex in sync (#569)
fix: update decaffeinate-parser dependency to keep coffee-lex in sync (#569)

decaffeinate and decaffeinate-parser need to share the same coffee-lex instance
or else singleton comparisons will fail, so this commit forces both decaffeinate
and decaffeinate-parser to depend on coffee-lex 4.x so they can use the same
instance.
eventualbuddha/decaffeinate,alangpierce/decaffeinate,decaffeinate/decaffeinate,alangpierce/decaffeinate,decaffeinate/decaffeinate,eventualbuddha/decaffeinate,alangpierce/decaffeinate