testing/spacebin: new aport

Spacebin (repository) is a pastebin server written in Go, working with or without javascript (use for text highlighting).

To upload a string of text:

curl -v -F content="Hello, world!" http://localhost:9000/ | jq payload.id

To upload from a file:

curl -v -F content=@helloworld.txt http://localhost:9000/ | jq payload.id

Example for APKBUILD