Bump version for Go 1.11 module

[nnkken]

Currently, the only tagged release version is v1.0.0, which is relatively old, and still using the Sirupsen/logrus import path instead of the new sirupsen/logrus one. This is causing build errors (case-insensitive conflict between the import paths) under Go 1.11 module system.

Would you consider marking a more recent commit as a new release version?

[xujinzheng]

current master is stable, I will tag it to v1.1.0