BiomeE segmentation fault

[stineb]

Continuous integration tests for BiomeE runs on Ubuntu sometimes throw an error (see for example here):

   *** caught segfault ***
  address 0x559f7bf30070, cause 'memory not mapped'
  Segmentation fault (core dumped)

This happens even after removing zero-indexed variables.

We should use additional gfortran compiler flags to catch problems at the stage of compilation. To be checked are the ones described on this post.