content-type missing in write-object

[Mossaka]

When putting a new object, many service require user to specify what content-type of that object will be, examples are "text/html". Currently in the blob-store interface, there is no way to specify content-type in write-object and write-stream.

[thomastaylor312]

@Mossaka We should probably do this before moving phases. Should we have a request-options resource that exposes some setters for a small subset of options? I was thinking at least:

• Content-Encoding
• Content-Length
• Content-MD5
• Content-Type

We might want to add the caching headers down the line, but for now this would get us the most important ones

[Mossaka]

yup that sounds good to me