uci 0.3.0

Major changes
- uci() now accepts columns with NA values. In such cases, NAs are replaced with zero as they represent zero activities.
- improved documentation
- The package now uses Queen contiguity (spdep::poly2nb(geo, queen=TRUE)) to determine neighboring polygons whe considering spatial link distances.
- Update vignette

uci 0.2.0

Major changes
- The uci function now has a new parameter dist_type that allows users to choose whether calculations should be based on "euclidean" distances (Default) or "spatial_link" distances. Spatial link distances consider Euclidean distances along the links of spatial neighbour links. In the case of areas with a concave shape (like a bay), it is strongly recommended to use "spatial_link" distances (even though they are computationally more costly) because simple Euclidean distances can bias UCI estimates in those cases.
- The uci function now has a new parameter parallel that speeds up calculations for large areas comprised with many polygons.
Minor changes
- Minor updates to documentation
- Performance improvments