Basic search support
Repaired travis tests, see wiki for installation instructions
Automatically update index (might not be a good idea in production)
Search on landing page working
Minor code cleanup
Fixed travis test
Fixes #69
Splitted requirements into separate files and folders
Forcing recompilation of psycopg2 on Travis, as it holds a broken version in its software repository.
Merge branch 'enhancement-splitted-requirements' into feature-search

Conflicts:
	openreview/requirements/pip/common.txt
Haystack-Elasticsearch breaks isolation of tests. Fixing
Fixed include tag in base.html
Updated tagline, improvements are welcome...
Added basic navigation
Simplify landing page header
Added navigation css to base.css
Moved a few css styles into general.css
merge
Added paper fixture
Started with paper reviews page
Use button tag instead