[studio] Update the `habitat/studio` Docker image creation to not cache.
[studio] Update the `habitat/studio` Docker image creation to not cache.

In this case, we don't want any prior layers--it's all new to us!

Signed-off-by: Fletcher Nichol <fnichol@nichol.ca>

Pull request: #592
Approved by: juliandunn

habitat-sh/habitat,habitat-sh/habitat,rsertelon/habitat,nathenharvey/habitat,habitat-sh/habitat,nathenharvey/habitat,nathenharvey/habitat,habitat-sh/habitat,habitat-sh/habitat,rsertelon/habitat,nathenharvey/habitat,rsertelon/habitat,georgemarshall/habitat,georgemarshall/habitat,georgemarshall/habitat,nathenharvey/habitat,nathenharvey/habitat,georgemarshall/habitat,georgemarshall/habitat,rsertelon/habitat,habitat-sh/habitat,georgemarshall/habitat,georgemarshall/habitat,rsertelon/habitat,rsertelon/habitat,rsertelon/habitat,georgemarshall/habitat,habitat-sh/habitat,habitat-sh/habitat