v1.1.1

Versioning v1.1.1 to correctly comply with SemVer.

CHANGELOG
03b6f63 Add AUTHORS file; update LICENSE (#158)
9ee0d62 [build] Update deps to correct SemVer tags (#153)
a2f2a3d replacing travis badge with scaling svg (#147)
92b749d Add link to XORM store implementation (#149)
7910f5b Added description about Max-Age field in Options (#148)
7087b4d Add go.mod file for vgo dependency management. (#145)
6ba88b7 Prevent panic in NewSession function (#140)
41ee504 Add link to memstore implementation (#143)
fe21b6a Update doc.go (#127)
a3acf13 Add missing error check (#123)