auto show a prompt to import package when typing un-import package name

[jiangyubao]

for example, when typing 'fmt.', we need a prompt to import fmt package

func main(){ fmt. }

after auto import, it will look like this:

import ( "fmt" ) func main(){ fmt. }

[parhamdoustdar]

:plus1:

[baconalot]

You can have auto-imports on format by replacing "gofmt" with "goimports". See #66

[parhamdoustdar]

It isn't automatic though. You have to type fmt., press ctrl+shift+F to format, and then press ctrl+space to get suggestions, for example.