go fmt
remove old exe leftover from previous update

Always try to remove the old file, but handle the case where the old
file doesn't exist.
cross-compiled builds

Enable cross-compiled builds for multiple platforms. Build for all known
platforms by default, but allow the user to specify a list of platforms
to be used instead. The process is:

* Clone the repo on BUILDBRANCH, determine the most recent release tag
  on that branch, and checkout that tag.
* For each specified platform:
  - Check if that build has already happened. If so, move on
  - Build
  - Upload
  - Cut release

If any of the individual platform builds fail, an error is logged, but
the build process continues for other platforms.

In order to guarantee reproducible builds on any platform, set
`CGO_ENABLED=0` to ensure that we always build statically-linked
binaries.
better hierarchy in S3 dist & patch buckets

Fixes #65.
correct upload filename
sort dyno list properly with >=10 dynos, fixes #53
move apps list into separate command
move dynos list into separate command
move releases list into separate command
breakout addons into separate command, remove ls
Split NewRequest() and DoReq() out of APIReq().

This will allow the caller to make changes to the API request (such as
adding headers where appropriate).
Use new v3 log-sessions API. Fixes #73.

Also remove Acceptor interface and url.Values option, they are no longer used.

Because of removed Acceptor interface, NewRequest no longer requires v.
Rename tail -p to -d to be consistent w/ 'dyno' noun
add .travis.yml
defer flushing the tabwriter
gofmt
properly document use of S3DISTURL env var
Remove parentheses
Add spaces
Use consistent indentation