Remove use of deprecated 'should_not raise_error(SpecificError)'

RSpec has since deprecated this construct. The recommended replacement

  @test.should_not raise_error

works just as well for us.

See: rspec/rspec-expectations#231
Add root .rspec config file to auto-require turnip

Took me a while to figure out that RSpec needed the '-r turnip/rspec'
option. Specifying it in the project RSpec config should save everyone
else the trouble.
Merge pull request #5 from benesch/matcher-description

Add description method to matchers
Merge pull request #6 from benesch/fix-tests

Fix tests
Merge pull request #7 from leomayleomay/add_attr_matcher

Add attribute matcher
version bump
fixes some oddly failing tests
quotes an XML attribute
version bump
Add travis control file
Add gem and travis badges to Readme
Dropped support of ruby 1.8