0.2.6

01bda82
Fix bug when merging partial to empty HTTP method

119c307
fix bug merging body

74d4b7c

Header callback, allows you to do this:

let response = await partial`
  url: https://google.com
  headers: ${partial => {
    if(partial.options.method === 'POST') return {...headers, 'Content-Type': 'application/json' }
    return headers
  }}
`