For CI - upgrade Window's version of MinGW compiler toolchain.

.travis.yml

@@ -134,9 +134,9 @@ environment:
   URHO3D_D3D11: 1
   URHO3D_LUAJIT: 1
   MINGW: 1
-  # MinGW-w64 on Windows is NOT multilib capable but we are installing the ones that support C++14 standard
-  x86_64-posix-seh: https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Personal%20Builds/mingw-builds/6.3.0/threads-posix/seh/x86_64-6.3.0-release-posix-seh-rt_v5-rev1.7z
-  i686-posix-dwarf: https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win32/Personal%20Builds/mingw-builds/6.3.0/threads-posix/dwarf/i686-6.3.0-release-posix-dwarf-rt_v5-rev1.7z
+  # MinGW-w64 on Windows is NOT multilib capable
+  x86_64-posix-seh: https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Personal%20Builds/mingw-builds/8.1.0/threads-posix/seh/x86_64-8.1.0-release-posix-seh-rt_v6-rev0.7z
+  i686-posix-dwarf: https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win32/Personal%20Builds/mingw-builds/8.1.0/threads-posix/dwarf/i686-8.1.0-release-posix-dwarf-rt_v6-rev0.7z
   matrix:
     - URHO3D_LIB_TYPE: STATIC
     - URHO3D_LIB_TYPE: SHARED
@@ -156,7 +156,7 @@ before_build:
           iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-desktop.ps1'))
         }
   - if "%PLATFORM%" == "x64" (set "URHO3D_64BIT=1" && set "MINGW_URL=%x86_64-posix-seh%" && set "ARCH=64") else (set "MINGW_URL=%i686-posix-dwarf%" && set "ARCH=32")
-  - if not exist "C:\tools\mingw%ARCH%" curl -fsSL -o "mingw.7z" -O "%MINGW_URL%" && 7z x -y -o"C:\tools" "mingw.7z" >nul && echo "Installed MinGW compiler toolchain to C:\tools"
+  - if not exist "C:\tools\mingw%ARCH%" curl -fsSLo "mingw.7z" "%MINGW_URL%" && 7z x -y -o"C:\tools" "mingw.7z" >nul && echo "Installed MinGW compiler toolchain to C:\tools"
   - set "PATH=C:\tools\mingw%ARCH%\bin;%PATH%"
 build_script:
   - rake ci && if "%PACKAGE_UPLOAD%" == "1" rake ci_package_upload