Fix include-path problem in testing
Fix include-path problem in testing

When spglib.h appears several times in directoies specified by -I, -iquote,
-isystem, or -idirafter, older spglib.h may be chosen (especially when
installing spglib and C compiler via conda). To fix the inconsistency,
use static library of `symspg.so` for testing. Then, src/spglib.h is
searched first since it locates the same directory as other src/*.c
files.

atztogo/spglib,atztogo/spglib,atztogo/spglib,atztogo/spglib,atztogo/spglib