Installation fails on Win7 xIntel64bit: Platform not Supported Error

## Description
Cannot install elm-format error indicated (see below). Attempted to install by issuing following command:

`npm install -g elm-format`

1.elm 0.18 installed using windows binary installer, not npm (using npm install -g elm downloads binaries but does not install, so decided to use windows installer instead).
2.Then proceeded to install elm-format but error below indicated
3.elm 0.18 is successfully installed and runs without issue.

## ### Error Indicated at npm install of elm-format
> elm-format@0.0.0 install C:\mydir\AppData\Roaming\npm\node_modules\elm-format
> node install.js

**_Unfortunately, there are no Elm Platform 0.0.0 binaries available for your operating system and architecture._**

If you would like to build Elm from source, there are instructions at https://github.com/elm-lang/elm-platform#build-from-source

npm ERR! Windows_NT 6.1.7601
npm ERR! argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modul
es\\npm\\bin\\npm-cli.js" "install" "-g" "elm-format"
npm ERR! node v6.9.2
npm ERR! npm v3.10.9
npm ERR! code ELIFECYCLE

## Environment
Win7 SP1
Intel Core i5 CPU x 64Bit

Start by reproducing `npm install -g elm-format` on the reported Windows 7 x64 environment and inspect the `install.js` step that reports unavailable binaries. Compare the package's supported platform and architecture data with this environment; done means the installation completes successfully or the limitation is documented clearly.

Written by the indexing model from the issue text.