triangle tests now conforming to canonical

[neenjaw]

• version bumped to 1.2.1
• trailing whitespace removed from README.md
• triangle.example and triangle_tests.plt:
  • There was some inconsistencies with the triangle predicate which @Average-user pointed out in non-exhaustive tests #81,
  • the tests were treating it like triangle(+Side1, +Side2, +Side3, +Type) but it was written in triangle.example to only be correct if used triangle(+Side1, +Side2, +Side3, -Type)
  • triangle.example has been changed now to pass the tests.

[Average-user]

@neenjaw Ok to merge?

[neenjaw]

I'm good if you're happy with it,

I thought I fixed the trailing newline on the version file, but it seems to be missing.

[Average-user]

Thats because there were conflicts with master. I think I fixed them but I never understood that tool weell enough. Will see after merge

[Average-user]

But do you want it with or without a newline at end?

[neenjaw]

I like it on, because then there isn't that symbol on the diff, but I can't push a commit for 30 minutes or so until I can get to a computer

[neenjaw]

Ready!