Use MSYS2 on appveyor
diff --git a/appveyor.yml b/appveyor.yml
index fb6ccd1..7c01515 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,13 +1,23 @@
 environment:
+  global:
+    MSYS2_BASEVER: 20150512
   matrix:
+  - TARGET: x86_64-pc-windows-gnu
+    MSYS2_ARCH: x86_64
+    MSYS2_BITS: 64
+    MSYSTEM: MINGW64
+  - TARGET: i686-pc-windows-gnu
+    MSYS2_ARCH: i686
+    MSYS2_BITS: 32
+    MSYSTEM: MINGW32
   - TARGET: x86_64-pc-windows-msvc
   - TARGET: i686-pc-windows-msvc
-  - TARGET: i686-pc-windows-gnu
 install:
+  - ps: ci\msys2.ps1
   - ps: Start-FileDownload "https://static.rust-lang.org/dist/rust-nightly-${env:TARGET}.exe"
   - rust-nightly-%TARGET%.exe /VERYSILENT /NORESTART /DIR="C:\Program Files (x86)\Rust"
   - SET PATH=%PATH%;C:\Program Files (x86)\Rust\bin
-  - SET PATH=%PATH%;C:\MinGW\bin
+  - if defined MSYS2_BITS set PATH=%PATH%;%CD%\msys2\mingw%MSYS2_BITS%\bin
   - rustc -V
   - cargo -V