Add support for godep to pin project dependencies

`godep` appears to be solid choice for pinning Go project dependencies.
This pull request contains a `Godeps` file with SHAs of dependency
revisions. Tests were run at the specified SHAs before freezing.
Merge pull request #30 from OpenTreeMap/hmc/godep-clean

Add support for godep to pin project dependencies.
Add a CHANGELOG.
Remove Godep binary from output bin directory

During the build process, the Godep binary was sneaking into the bin
directory, which gets rolled up into a tarball for releases.
Merge pull request #33 from OpenTreeMap/hmc/rm-godep-bin

Remove Godep binary from output bin directory.
Setup project dependencies with Godep and -copy=true

Godep is moving away from the current format we're using to reference
dependencies. Instead, Godep is moving toward a workflow that vendors
all Go dependencies under the `Godeps/` directory.

Warnings have been added to the Godep source code when using the
-copy=false method:

  https://github.com/tools/godep/blob/master/go.go#L169-L177

Further discussion on the change:

  http://goo.gl/RpYs8e
Merge pull request #34 from OpenTreeMap/hmc/godep-round-2

Setup project dependencies with Godep and -copy=true
Wrap development and build workflow in Vagrant and Make

In order make the process of developing against or building this project
easier, this pull request wraps everything inside of a Vagrant project.
In addition to Vagrant, Ansible is used to provision the Vagrant virtual
machine.

Resolves #23.
Merge pull request #35 from OpenTreeMap/hmc/ansible-vagrant

Wrap development and build workflow in Vagrant and Make