feat: implement ghq rm command

[Okabe-Junya]

close #299

Feature Description

• implement ghq rm command
• add unit test (for ghq rm)
• update README
• update CREDIT

How to use

ghq rm [--dry-run] <project>|<user>/<project>|<host>/<user>/<project>

Example

build

$ pwd
/Users/junya/src/github.com/Okabe-Junya/ghq

$ make build
go get  -d 
go mod tidy
go build  -ldflags="-s -w -X main.revision=9c9fc5a"

$ ls | grep ghq
ghq

Create a sample repo (by using the ghq command)

$ ./ghq create foo      
       git init
Initialized empty Git repository in /Users/junya/src/github.com/junya/foo/.git/
/Users/junya/src/github.com/junya/foo

$ ghq list | grep foo
github.com/junya/foo

Execute the ghq rm command

$ ./ghq rm --dry-run foo
Would remove /Users/junya/src/github.com/junya/foo

$ ./ghq rm foo          
Remove /Users/junya/src/github.com/junya/foo? [y/N]: y
Removed /Users/junya/src/github.com/junya/foo

$ ghq list | grep foo   

$ 

Of course, it is also possible to specify the repo in the <host>/<user>/<project> format.

$ ./ghq rm --dry-run github.com/Okabe-Junya/ghq
Would remove /Users/junya/src/github.com/Okabe-Junya/ghq

[Okabe-Junya]

@Songmu @motemen

Hi!! Thank you for the wonderful software!! I use it all the time.

I would be pleased if you could review this PR. I'm not in a hurry, so when you have time, please check.

[Songmu]

Thanks for adding the new feature! Released as v1.5.0.