Fix CRAN version

[gvegayon]

I got an email from CRAN indicating that the package had some issues that needed to be addressed (here). The message that some R installs are giving is the following:

Check Details
Version: 0.3-1
Check: Rd cross-references
Result: NOTE 
  Found the following Rd file(s) with Rd \link{} targets missing package
  anchors:
    nvertex.Rd: network
  Please provide package anchors for all Rd \link{} targets not in the
  package itself and the base packages.
Flavors: [r-devel-linux-x86_64-debian-clang](https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-debian-clang/ergmito-00check.html), [r-devel-linux-x86_64-debian-gcc](https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-debian-gcc/ergmito-00check.html), [r-devel-windows-x86_64](https://www.r-project.org/nosvn/R.check/r-devel-windows-x86_64/ergmito-00check.html), [r-patched-linux-x86_64](https://www.r-project.org/nosvn/R.check/r-patched-linux-x86_64/ergmito-00check.html), [r-release-linux-x86_64](https://www.r-project.org/nosvn/R.check/r-release-linux-x86_64/ergmito-00check.html), [r-release-windows-x86_64](https://www.r-project.org/nosvn/R.check/r-release-windows-x86_64/ergmito-00check.html)

Version: 0.3-1
Check: installed package size
Result: NOTE 
    installed size is  5.6Mb
    sub-directories of 1Mb or more:
      libs   4.2Mb
Flavors: [r-oldrel-macos-arm64](https://www.r-project.org/nosvn/R.check/r-oldrel-macos-arm64/ergmito-00check.html), [r-oldrel-macos-x86_64](https://www.r-project.org/nosvn/R.check/r-oldrel-macos-x86_64/ergmito-00check.html)

Need to identify the issue with the notes and correct them preparing for the next CRAN release.