Resolves #150: RSpec redesign

* Conversion to RSpec's `expect` syntax.
Update history
Merge branch 'rspec-cleanup' of https://github.com/duggiefresh/nmatrix into duggiefresh-rspec-cleanup

Conflicts:
	spec/00_nmatrix_spec.rb
Merge branch 'master' of github.com:SciRuby/nmatrix