Module path should be "github.com/liu2hai/chive", not "chive"

[KateGo520]

Background

Module path is inconsistent with go import path.
GO111MODULE=on, run go get github.com/liu2hai/chive:

go: downloading github.com/liu2hai/chive v0.0.0-20190817071450-4062106be942
go: github.com/liu2hai/chive upgrade => v0.0.0-20190817071450-4062106be942
go get: github.com/liu2hai/chive@v0.0.0-20190817071450-4062106be942: parsing go.mod:
        module declares its path as: chive
                but was required as: github.com/liu2hai/chive 

Solution

Fix the module path:

1. Rename the module path to "github.com/liu2hai/chive": https://github.com/liu2hai/chive/blob/master/go.mod#L1

module github.com/liu2hai/chive
go 1.12
require (
	…
) 

2. Warning the users not to use the module, get "github.com/liu2hai/chive" in GOPATH mode.

[KateGo520]

@liu2hai Could you help me review this issue? Thx :p