Wildcard in element_composition probably not working correctly

[gasevic]

The element_composition setting in the mindlessgen.toml file allows for wildcard integer values e.g. with

element_composition = "Ga:1-*"

but all structures that come out only include the minimum count instead of random integer numbers.

[marcelmbn]

Due to the principle of the code, this is basically a copy of #76.
Will close this issue with the above one as soon as it's resolved.