Add installation instructions for Rails 5.0
Add installation instructions for Rails 5.0

biow0lf/shoulda-matchers,thoughtbot/shoulda-matchers,reacuna/shoulda-matchers,biow0lf/shoulda-matchers,biow0lf/shoulda-matchers,guialbuk/shoulda-matchers,guialbuk/shoulda-matchers,reacuna/shoulda-matchers,thoughtbot/shoulda-matchers,reacuna/shoulda-matchers,reacuna/shoulda-matchers,guialbuk/shoulda-matchers,thoughtbot/shoulda-matchers,guialbuk/shoulda-matchers,biow0lf/shoulda-matchers,thoughtbot/shoulda-matchers