Appveyor deployment install ffmpeg

appveyor.yml

image: Visual Studio 2017

environment:
  ffmpeg_download: https://ffmpeg.zeranoe.com/builds/
  matrix:
    - platform: x64
      nodejs_version: LTS
      ffmpeg_version: 3.4.1
      ffmpeg_platform: win64

    - platform: x64
      nodejs_version: Current
      ffmpeg_version: latest
      ffmpeg_platform: win64

    - platform: x86
      nodejs_version: LTS
      ffmpeg_version: 3.4.1
      ffmpeg_platform: win32

    - platform: x86
      nodejs_version: Current
      ffmpeg_version: latest
      ffmpeg_platform: win32

cache:
  - node_modules

install:
  - ps: Install-Product node $env:nodejs_version $env:platform
  - npm install
  - ps: Start-FileDownload $env:ffmpeg_download$env:ffmpeg_platform/static/ffmpeg-$env:ffmpeg_version-$env:ffmpeg_platform-static.zip
  - 7z x ffmpeg-%ffmpeg_version%-%ffmpeg_platform%-static.zip
  - PATH=%PATH%;%cd%\ffmpeg-%ffmpeg_version%-%ffmpeg_platform%-static\bin
  - ps: $env:package_version = (Get-Content -Raw -Path package.json | ConvertFrom-Json).version
  - ps: Update-AppveyorBuild -Version "$env:package_version-$env:APPVEYOR_REPO_BRANCH-$env:APPVEYOR_BUILD_NUMBER"

test_script:
  - ffmpeg -version
  - node --version
  - npm --version
  - npm test

on_success:
  - npm run examples
  - npm run out

build: off