Add OSF Guideline for using url lookups in Mako
Add note about using unittest.skip when stubbing tests

Also add links to webtest/webtest+
Fix typo denoting code block on OSF Guidelines
Merge pull request #6 from lyndsysimon/edits

Edits: OSF Guidelines
Fix GFortran URL, add a missing step
Add .DS_Store to .gitignore
Remove .DS_Store
Merge pull request #7 from csheldonhess/master

Fix GFortran URL, add a missing step
Remove ignored DS_Store file
Add notes about doing Ubuntu EOL upgrades
Add example model and views tests
A small note re: test names
An important note re: hotfix branches
Add a how-to section for releases
Add section on JS linting; fix typos in Python linter section
Document how to get current node in a view function
Update naming conventions for $.ajax h/t @brianjgeiger
Document client-side error handling
Document invoke task for finishing hotfixes
Correct invoke task