[likelihood_ratio_processes_2] Update new exercises with learning agents (#566)

* update exercises

* updates

* updates

* Tom's edits of Blume-Easley lecture and bib file

* update new exciting exercises

* minor updates

* minor updates

* updates

* Tom's August 21 edits of Humphrey's two new exercises

* Tom's second Aug 21 edits of the BE lecture

* updates

* update parameters

* minor updates

* remove redundent imports

---------

Co-authored-by: thomassargent30 <ts43@nyu.edu>
Co-authored-by: Matt McKay <mmcky@users.noreply.github.com>

Author: 3 people

lectures/_static/quant-econ.bib

@@ -3,6 +3,16 @@
 Note: Extended Information (like abstracts, doi, url's etc.) can be found in quant-econ-extendedinfo.bib file in _static/
 ###
 
+@article{blume2018case,
+  title={A case for incomplete markets},
+  author={Blume, Lawrence E and Cogley, Timothy and Easley, David A and Sargent, Thomas J and Tsyrennikov, Viktor},
+  journal={Journal of Economic Theory},
+  volume={178},
+  pages={191--221},
+  year={2018},
+  publisher={Elsevier}
+}
+
 @article{shannon1948mathematical,
   title={A mathematical theory of communication},
   author={Shannon, Claude E},