move to jquery-1.11.1 to fix upcoming CSP violations

The CSP header we're planning to land will run afoul of some feature-detection code in the current jquery-1.10.2 . Moving to 1.11.1 fixes that. My quick tests suggest that nothing is broken by this, but please double-check that fact before merging.

This change also needs to happen in `app/tests/main.js`.