Bump windows CI version

sfackler · web-flow · commit 3ea5d8db243b · 2019-09-04T19:06:19.000-04:00
diff --git a/appveyor.yml b/appveyor.yml
@@ -1,5 +1,5 @@
 environment:
-  RUST_VERSION: 1.26.2
+  RUST_VERSION: 1.30.0
   TARGET: x86_64-pc-windows-msvc
 install:
   - ps: Start-FileDownload "https://static.rust-lang.org/dist/rust-${env:RUST_VERSION}-${env:TARGET}.exe"
