Fix miktex install on appveyor

appveyor.yml

@@ -57,19 +57,21 @@ install:
   # Check that we have the expected version and architecture for Python
   - "python --version"
   - "python -c \"import struct; print(struct.calcsize('P') * 8)\""
-
-  # Install miktex to get pdflatex, if we don't get it from the cache
-  - if not exist c:\miktex\texmfs\install\miktex\bin\pdflatex.exe appveyor DownloadFile http://mirrors.ctan.org/systems/win32/miktex/setup/windows-x86/miktex-portable.exe
-  - if not exist c:\miktex\texmfs\install\miktex\bin\pdflatex.exe 7z x miktex-portable.exe -oC:\miktex >NUL
-  - set "PATH=%PATH%;c:\miktex\texmfs\install\miktex\bin"
+
+  # stolen from https://github.com/doxygen/doxygen/blob/master/appveyor.yml
+  - appveyor-retry appveyor DownloadFile  https://miktex.org/download/win/miktexsetup-x64.zip
+  - 7z e miktexsetup-x64.zip
+  - appveyor-retry miktexsetup.exe --local-package-repository=C:\miktex-repository --package-set=essential download
+  - miktexsetup.exe --local-package-repository=C:\miktex-repository --package-set=essential --shared install
+  - refreshenv
   # autoinstall latex packages (0=no, 1=autoinstall, 2=ask)
   # this adds this to the registry!
-  - initexmf --set-config-value "[MPM]AutoInstall=1"
+  - initexmf --admin --set-config-value "[MPM]AutoInstall=1"
 
 
   # Upgrade to the latest version of pip to avoid it displaying warnings
   # about it being out of date.
-  - "pip install --disable-pip-version-check --user --upgrade pip"
+  - "%CMD_IN_ENV% python -m pip install --disable-pip-version-check --user --upgrade pip"
 
   - "%CMD_IN_ENV% python -m pip install twine wheel"