Nim v1.2.14 released

[arnetheduck]

It is possible to write code that works with both 1.2 and 1.6, but in our 1.2 
codebase, practically every library needs some sort of update to compile (we 
haven't gotten as far as testing actually running it) - 1.4 unfortunately 
contained many breaking changes - with 1.6, significant work has been done to 
reduce the surface area of breaking changes with new stability policies, which 
is great news!