[appveyor] Use out-of-tree build and cache

Author: xoviat

appveyor.yml

@@ -23,6 +23,9 @@ skip_commits:
 # Add [av skip] to commit messages
   message: /\[av skip\]/
 
+cache:
+  - %APPVEYOR_BUILD_FOLDER%\build
+
 environment:
   global:
     CONDA_INSTALL_LOCN: C:\\Miniconda36-x64
@@ -44,12 +47,12 @@ install:
   - if [%COMPILER%]==[clang-cl] set "CPATH=%CONDA_INSTALL_LOCN%\Library\include;%CPATH%"
 
 before_build:
-  - echo Running cmake...
-  - cd c:\projects\OpenBLAS
-  - if [%COMPILER%]==[cl] cmake -G "Visual Studio 12 Win64" .
-  - if [%WITH_FORTRAN%]==[no] cmake -G "Ninja" -DCMAKE_CXX_COMPILER=clang-cl -DCMAKE_C_COMPILER=clang-cl .
-  - if [%WITH_FORTRAN%]==[yes] cmake -G "NMake Makefiles" -DCMAKE_CXX_COMPILER=clang-cl -DCMAKE_C_COMPILER=clang-cl -DCMAKE_Fortran_COMPILER=flang -DBUILD_WITHOUT_LAPACK=no -DNOFORTRAN=0 .
-  - if [%DYNAMIC_ARCH%]==[ON] cmake -DDYNAMIC_ARCH=ON .
+  - ps: if (-Not (Test-Path .\build)) { mkdir build }
+  - cd build
+  - if [%COMPILER%]==[cl] cmake -G "Visual Studio 12 Win64" ..
+  - if [%WITH_FORTRAN%]==[no] cmake -G "Ninja" -DCMAKE_CXX_COMPILER=clang-cl -DCMAKE_C_COMPILER=clang-cl ..
+  - if [%WITH_FORTRAN%]==[yes] cmake -G "NMake Makefiles" -DCMAKE_CXX_COMPILER=clang-cl -DCMAKE_C_COMPILER=clang-cl -DCMAKE_Fortran_COMPILER=flang -DBUILD_WITHOUT_LAPACK=no -DNOFORTRAN=0 ..
+  - if [%DYNAMIC_ARCH%]==[ON] cmake -DDYNAMIC_ARCH=ON ..
 
 build_script:
   - cmake --build .