Add 'publish' action in script builder

We want to separate 'save' and 'publish'.

The way to publish is to trigger a build of the latest master in the hasadna/reportit-scripts repo on travis CI.

https://docs.travis-ci.com/user/triggering-builds/

In short, you need to make a POST request to
`https://api.travis-ci.org/repo/hasadna%2Freportit-scripts/requests`
With the following headers:
- `Travis-API-Version: 3`
- `Authorization: token `

And the following body:
```
{
"request": {
"branch":"master"
}
}
```