fixes #158
first version of #157
updated README with builder examples
added deprecations for unused matrix sources
working on #159
fixes #159
updated changelog
fixed issue with random matrix generation
added matrix source
updated CHANGELOG
decided to left the random matrix source
fixes #157
refactored random vector source
fixed a couple of typos in matrix package
improved vector package docs
working on #166
working on #167
updated the changelog
fixes #167
removed diagonal matrix source; updated changelog