This limit shouldn't be enforce by the library

[Isaac Sanders]

https://github.com/hexpm/hex_core/blob/a708f382f1b2e34b1d49adac18af8ce35c969af4/src/hex_tarball.erl

This is related to hexpm/hex#766.

This should be enforced by the repo implementation, not the core library.

[Eric Meadows-Jönsson]

hex_core should enforce a default but it should be overridable by configuration.

[Isaac Sanders]

Closed by #93