Refactored 'AppVeyor' config, 'ARDUINO_SDK_PATH' is no longer hardcoded.

Author: MrPointer

appveyor.yml

@@ -2,23 +2,24 @@ version: '{build}'
 image: Visual Studio 2017
 environment:
   MINGW_PATH: C:\mingw-w64\x86_64-7.2.0-posix-seh-rt_v5-rev1\mingw64\bin
+  ARDUINO_SDK_BASE_PATH: C:\arduino-sdk\arduino
   matrix:
   - ARDUINO_SDK_VERSION: 1.8.2
-    ARDUINO_SDK_PATH: C:\arduino-sdk\arduino-1.8.2
   - ARDUINO_SDK_VERSION: 1.8.7
-    ARDUINO_SDK_PATH: C:\arduino-sdk\arduino-1.8.7
 cache:
-- '%ARDUINO_SDK_PATH%'
+- '%ARDUINO_SDK_BASE_PATH%-%ARDUINO_SDK_VERSION%'
 install:
 - ps: cinst unzip
 - ps: $sdk_file = "arduino-$env:ARDUINO_SDK_VERSION-windows.zip"
+# Append SDK's version to SDK's base path
+- ps: $env:ARDUINO_SDK_PATH = "$env:ARDUINO_SDK_BASE_PATH-$env:ARDUINO_SDK_VERSION"
 - ps: cd C:\
 - ps: |
     if ( -Not (Test-Path -Path $env:ARDUINO_SDK_PATH) )
     {
-      $arduino_sdk_uri = "https://downloads.arduino.cc/$sdk_file"
-      wget "$arduino_sdk_uri" -O "$sdk_file"
-      unzip "$sdk_file" -d "arduino-sdk"
+    $arduino_sdk_uri = "https://downloads.arduino.cc/$sdk_file"
+    wget "$arduino_sdk_uri" -O "$sdk_file"
+    unzip "$sdk_file" -d "arduino-sdk"
     }
 - ps: $env:ARDUINO_SDK_PATH = ($env:ARDUINO_SDK_PATH -replace "\\","/")
 - ps: $env:Path += ";$env:MINGW_PATH"