Removed NVector ruby file
Removed mentions to NVector from ext/
Remove commented out `yard` dependency
Removes unused variable within /nmatrix/io/matrix
Remove unused Guardfile

* `guard-rspec` isn't being included within the project, so we ought to
  remove this file.
spec/io-spec: `let` instead of instance variables
spec/01_enum_spec: `let` instead of instance variables
Merge pull request #239 from agarie/remove_nvector

Remove most of deprecated NVector mentions
Merge pull request #240 from duggiefresh/remove-yard-dependency

Remove commented out `yard` dependency
Merge pull request #242 from duggiefresh/remove-unused-variable

Removes unused variable within /nmatrix/io/matrix
Merge pull request #245 from duggiefresh/remove-unused-guardfile

Remove unused Guardfile
Merge pull request #246 from duggiefresh/io-spec-remove-instance-variables

spec/io-spec: `let` instead of instance variables
Merge pull request #247 from duggiefresh/enum-spec-remove-instance-variables

spec/01_enum_spec: `let` instead of instance variables