Update CI URLs to point to new caching infrastructure

Author: staticfloat

appveyor.yml

@@ -1,12 +1,13 @@
 environment:
   matrix:
-    - JULIAVERSION: "julianightlies/bin/winnt/x86/julia-latest-win32.exe"
-    - JULIAVERSION: "julianightlies/bin/winnt/x64/julia-latest-win64.exe"
+    - JULIA_URL: "https://julialangnightlies-s3.julialang.org/bin/winnt/x86/julia-latest-win32.exe"
+    - JULIA_URL: "https://julialangnightlies-s3.julialang.org/bin/winnt/x64/julia-latest-win64.exe"
 
 install:
+  - ps: "[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.SecurityProtocolType]::Tls12"
 # Download most recent Julia Windows binary
   - ps: (new-object net.webclient).DownloadFile(
-        $("http://s3.amazonaws.com/"+$env:JULIAVERSION),
+        $env:JULIA_URL,
         "C:\projects\julia-binary.exe")
 # Run installer silently, outPut to C:\projects\julia
   - C:\projects\julia-binary.exe /S /D=C:\projects\julia