manylinux: Test installation with --user

To address:

  Installing collected packages: itk-core, itk-numerics, itk-io,
  itk-filtering, itk-segmentation, itk-registration, itk
  Could not install packages due to an EnvironmentError: [Errno 13]
  Permission denied: '/opt/_internal/cpython-3.7.0/_skbuild'
  Consider using the `--user` option or check the permissions.

Author: thewtex

scripts/internal/manylinux-build-wheels.sh

@@ -144,8 +144,8 @@ done
 
 # Install packages and test
 for PYBIN in "${PYBINARIES[@]}"; do
-    ${PYBIN}/pip install numpy
-    ${PYBIN}/pip install itk --no-cache-dir --no-index -f /work/dist
+    ${PYBIN}/pip install --user numpy
+    ${PYBIN}/pip install itk --user --no-cache-dir --no-index -f /work/dist
     (cd $HOME && ${PYBIN}/python -c 'from itk import ITKCommon;')
     (cd $HOME && ${PYBIN}/python -c 'import itk; image = itk.Image[itk.UC, 2].New()')
     (cd $HOME && ${PYBIN}/python -c 'import itkConfig; itkConfig.LazyLoading = False; import itk;')