Update excon dependency to version ~>0.24.0
Merge pull request #1891 from sferik/update_excon_dependency

Update excon dependency to version ~>0.24.0
Introduce coveralls.io and simplecov
Add shindo_helper to all tests
See if this helps with the files that contain UTF-8 characters.
Revert "Add shindo_helper to all tests"

This reverts commit f29a24b4858e7604d5b6c72ce7343a9d9974e67a.
Try to get coveralls to run at the end only
Use rake test:travis, which will run shindont and push results to coveralls.