Appveyor: use pre-installed Qt and upgrade Boost to 1.66

appveyor.yml

@@ -39,7 +39,7 @@ install:
 
   # Boost
   # 1.63 is already installed on appveyor, just use it
-  - set BOOST_ROOT=C:\Libraries\boost_1_63_0
+  - set BOOST_ROOT=C:\Libraries\boost_1_66_0
   - set CMAKE_PREFIX_PATH=%CMAKE_PREFIX_PATH%;%BOOST_ROOT%
 
   # Install a bunch of vcpkg dependencies. We rely on the run-to-run caching
@@ -71,15 +71,19 @@ install:
   - vcpkg install ragel:x64-windows
   - vcpkg install sqlite3:x64-windows
 
+  # Qt
+  - set CMAKE_PREFIX_PATH=%CMAKE_PREFIX_PATH%;C:\Qt\5.12
+
+
   # Expensive optional deps only build if there's plenty of time left.
   # If we run out the clock, the cache won't be saved.
-  - ps: |
-        $OIIO_BUILD_NOW=Get-Date
-        if (($OIIO_BUILD_NOW-$OIIO_INSTALL_BEGIN).TotalMinutes -gt 15) {
-            Add-AppveyorMessage -Message "OIIO low on time, skippping dependency qt5-base"
-        } else {
-            vcpkg install qt5-base:x64-windows
-        }
+  # - ps: |
+  #       $OIIO_BUILD_NOW=Get-Date
+  #       if (($OIIO_BUILD_NOW-$OIIO_INSTALL_BEGIN).TotalMinutes -gt 15) {
+  #           Add-AppveyorMessage -Message "OIIO low on time, skippping dependency qt5-base"
+  #       } else {
+  #           vcpkg install qt5-base:x64-windows
+  #       }
 
   # Wish list:
   #   OpenCV