Log Message:
p5-Sereal: update to 4.018.

4.018 Thurs Aug 3, 2020
    * Fix issue with gcc 10 with snappy compression.

4.017 Thurs July 9, 2020
    * The build fixes in 4.016 didn't work correctly, this should fix them.

4.016 Thurs July 9, 2020
    * Fix some dependency issues in build process

4.015 Weds  July 8, 2020
    * Build fixes (missing dependency)
    * Hardening against corrupted data
    * New thresholds to manage decoding process