appveyor: Correct path for git clone and skip artefact archival

.appveyor.yml

@@ -47,6 +47,8 @@ platform: x64
 
 init:
   - git config --global core.autocrlf input
+
+before_build:
   - 'FOR /F "tokens=* USEBACKQ" %%F IN (`C:\cygwin64\bin\cygpath -u %AV_TIFF_SOURCE%`) DO SET AV_TIFF_CYG_SOURCE=%%F'
   - 'FOR /F "tokens=* USEBACKQ" %%F IN (`C:\cygwin64\bin\cygpath -u %AV_TIFF_INSTALL%`) DO SET AV_TIFF_CYG_INSTALL=%%F'
   - 'if %compiler%==cygwin-cmake C:\Cygwin64\setup-x86_64 -q -R C:\Cygwin64 -s http://cygwin.mirror.constant.com -l %AV_TIFF_DOWNLOAD%\cygwin -P cmake,libjpeg-devel,zlib-devel'
@@ -60,8 +62,6 @@ init:
   - 'if %compiler%==cygwin-cmake set "AV_TIFF_CMAKE_SOURCE=%AV_TIFF_CYG_SOURCE%'
   - 'if %compiler%==cygwin-cmake set "AV_TIFF_CMAKE_INSTALL=%AV_TIFF_CYG_INSTALL%'
   - 'if %compiler%==vc14-nmake call "%VS140COMNTOOLS%..\..\VC\vcvarsall.bat" %platform%'
-
-before_build:
   - mkdir %AV_TIFF_BUILD%
   - cd %AV_TIFF_BUILD%
   - if NOT %compiler%==vc14-nmake echo Running cmake -G "%generator%" -DCMAKE_INSTALL_PREFIX=%AV_TIFF_CMAKE_INSTALL% -DCMAKE_BUILD_TYPE=%configuration% %AV_TIFF_CMAKE_SOURCE%
@@ -102,8 +102,10 @@ before_test:
   - 'if %compiler%==vc14-cmake ctest -V -C %configuration%'
 # vc14-nmake does not support unit tests
 
-artifacts:
-  - path: libtiff.zip
-    name: libtiff.zip
-  - path: libtiff-build.zip
-    name: libtiff-build.zip
+# AppVeyor don't yet have a configurable retention policy, so this will
+# eventually use up all the storage allowance.
+#artifacts:
+#  - path: libtiff.zip
+#    name: libtiff.zip
+#  - path: libtiff-build.zip
+#    name: libtiff-build.zip