BUG: Fixes bug, adds unittest to prevent, adds exception handling, and include CI

[linwoodc3]

This is a bug fix to something I unknowingly causes in the merge request a month ago. The CI piece is trial and error so that's why there are so many. The code changes are minimal. More importantly, it fixes a bug likely causes by me and makes it so no one else can break good-morning.

• urllib2 gone and replaced with @petercerno original code
• updated readme; added example of financials class
• created a tests folder with 3 simple unit tests; make sure a break like this doesn't happen again
• Includes exception handling (unit test included)
  • exception for someone entering an empty string
  • exception for someone entering an incorrect ticket symbol
• Include continuous integration to run unittests anytime some requests a pull requests.
  • Requires action from @petercerno , but will limit time spent reviewing pull requests
  • Action: Just add Travis CI and Appveyor to your github.

To add CI to good-morning it only takes a few clicks:

1. Follow instructions here: https://docs.travis-ci.com/user/getting-started/#To-get-started-with-Travis-CI
2. Follow instructions here: https://www.appveyor.com/docs/#step-1---sign-in-with-appveyor

Travis gives coverage for Linux and OSX; Appveyor gives coverage for Windows.

Now, when anyone does a pull request, the unit tests launch automatically, and if it doesn't pass, you know the pull request breaks good-morning.

[linwoodc3]

Closes #6. Closes #7

[petercerno]

I really appreciate your contribution and your enthusiasm for the project. Unfortunately, I cannot accept your pull request in the current form (as it is a bundle of two independent changes). Would it be possible to create another pull request containing only the bug fix (and nothing else)?

I do not want to add the CI code as it adds unnecessary complexity, i.e. I prefer to keep the code as simple as possible (without any distractions), and the library as small as possible.

[linwoodc3]

No unittests either? That will check to see if the url return has changed or not.

[linwoodc3]

And being transparent, the enthusiasm is around the utility of the code. I can use this library for "Buffett-style" security analysis, so, it helps me. :-)

[petercerno]

Ah, sorry, yes it is perfectly fine to add unit tests. Maybe add a small comment about how to run the unit tests (either in README, or the unit tests themselves). Thanks a lot!