Option to ignore ConnectionError.

Ignore ConnectionError during init_app() for testing/development.

Prepared for tests in setup.py.
Testing read_config, added coverage reports.

Made read_config more testable, it only needs access to app.config dictionary
instead of the entire app instance.

Added testcovweb command to setup.py.
Fixed errors in 2.6 and 3.x.
Logging, more tests, better fake method.

Log when ConnectionError is ignored.
Using a class method instead of a lambda for fake function. This is more
appropriate as I'm overwriting a class instance method.
Finished writing tests.
One more test. 100% coverage yeaaaahhh!
Letting PyCharm resort my imports.
Updated README.
Merge pull request #3 from Robpol86/ignoreerror

Added JIRA_IGNORE_INITIAL_CONNECTION_FAILURE option.