Feature Request: Ability to rename andchmod resultant file

[osterman]

what

• I wish that we could specify the octal mode of the file download from the github release
• I wish that we could specify the destination name

why

• So that I can set the execution bit (E.g. 0755) without calling chmod explicitly
• Extremely common usage pattern is to download binary releases of apps (e.g. fetch) and then run them

example interface

fetch --repo https://github.com/gruntwork-io/fetch \
      --tag=v0.2.0 \
      --release-asset=fetch_darwin_amd64 \
      --asset-name=fetch \
      --asset-file-mode=0755 \
        /usr/local/bin

[brikis98]

--asset-file-mode and --asset-file-destination both sound like a great idea for optional params. We'd welcome a PR to add those!