release-1.7.1

This release includes two minor changes:

• GOTO becomes optional in IF statements:
  • #83
• Added support for go modules:
  • #74

The former change is the only user-visible one, and it allows the following two lines to be treated as identical:

• 10 IF A < 10 THEN GOTO 300 ELSE GOTO 400
• 10 IF A < 10 THEN 300 ELSE 400