Add test for interpolation

Jenkinsfile

configure.ac

coverage.sh

src/csds_cosmology.h

src/csds_error.h

src/csds_fields.h

src/csds_hashmap.h

src/csds_header.h

src/csds_inline.h

src/csds_interpolation.h

src/csds_loader_io.h

src/csds_logfile_writer.h

src/csds_openmp.h

src/csds_particle.h

src/csds_python_tools.h

src/csds_python_wrapper.c

tests/Makefile.am

tests/testInterpolation.c

tests/test_interpolation.yml