ergmito 0.3-1

ergmito 0.3-0

Added a NEWS.md file to track changes to the package.
A new argument model_update has been added to ergmito, ergmito_formulae, and gof_ergmito (GOF_update). This new feature allows users adding offset terms (which is now supported) and arbitrary updates to the model, for example, including interaction terms.
Fixed bug in ergmito_boot. The covariance matrix was estimated with the wrong sample, sometimes taking observations with missing.
Better memory management: ergmito_ptr (a C++ class) was duplicating memory when it was not supposed to. A new implementation avoids copying memory and thus makes it faster when trying to fit a larger object.
The dots in the function parameter target.stats, stats.statmat, and stats.weights have been replaces with underscores (better naming practices).
A new benchmark function has been added, benchmarkito. The idea is to have a dependency-free way to run benchmarks. This is not the most accurate alternative, but is good enough for the package.
The function new_rergmito has been refactored.