Warning messages when using `k2k = TRUE`

[ngreifer]

In k2k(), many warnings appear due to the following lines:

https://github.com/IQSS/cem/blob/de93f7ef8b71fda3f9c117f836207002dc00cd02/R/k2k.R#L117-L118 https://github.com/IQSS/cem/blob/de93f7ef8b71fda3f9c117f836207002dc00cd02/R/k2k.R#L129-L130

This is because on line https://github.com/IQSS/cem/blob/de93f7ef8b71fda3f9c117f836207002dc00cd02/R/k2k.R#L113 min() is run on a column of all NAs. I know the point of the NA is to exclude those units from future matching because they have already been matched. If you replace all the NAs with Infs, you will get the same results without the unnecessary warnings.