Added automated tweet ability to news items.
Added url field to news items and adjusted URL sent in tweets.
Added page for posting new news items.
Added python-twitter to list of packages to install during build tests.
Implemented OpenSearch (closes #40).
Fixed absolute paths in OpenSearch (closes #40).
Added PIP requirements.txt file to simplify installation of dependencies (closes #41).
Updated build script to use requirements.txt for installing required Python packages.