Update README.markdown

Fix required Erlang version from R14B01 to R16B01

the requirement to have Erlang verions >= R14B01 was incorrect since the following commit to master:
https://github.com/okeuday/uuid/commit/4a6b95b1412d2da7cf33be64e74d2b821123c040
Merge pull request #11 from Cy6erBr4in/patch-1

Update README.markdown