Added support for Elasticsearch 1.5.2

Elasticsearch 0.90.x is quite out-of-date, and this requirement is preventing us from sharing an ES cluster with newer IDAs.

ECOM-3261 and SOL-295

.travis/docker-compose-travis.yml

@@ -12,7 +12,7 @@ services:
       MYSQL_PASSWORD: "secret"
       MYSQL_DATABASE: "edx_notes_api"
   es:
-    image: edxops/elasticsearch:0.9.13
+    image: elasticsearch:1.5.2
     container_name: es
   notes:
     # Uncomment this line to use the official course-discovery base image

README.rst

@@ -10,13 +10,12 @@ This is a backend store for edX Student Notes.
 Overview
 --------
 
-The edX Notes API is designed to be compatible with the
-`Annotator <http://annotatorjs.org/>`__. Can be run with up to date ElasticSearch or legacy 0.90.x.
+The edX Notes API is designed to be compatible with the `Annotator <http://annotatorjs.org/>`__.
 
 Getting Started
 ---------------
 
-1. You'll need an `ElasticSearch <http://elasticsearch.org>`__ installed.
+1. Install `ElasticSearch 1.5.2 <https://www.elastic.co/blog/elasticsearch-1-5-2-and-1-4-5-released>`__.
 
 2. Install the requirements:
 

requirements/base.txt

@@ -2,8 +2,8 @@ Django==1.8.7
 requests==2.4.3
 djangorestframework==3.2.3
 django-rest-swagger==0.2.0
-django-haystack==2.3.1
-elasticsearch==0.4.5  # only 0.4 works for ES 0.90
+django-haystack==2.6.0
+elasticsearch>=1.0.0,<2.0.0
 django-cors-headers==1.1.0
 PyJWT==0.3.0
 MySQL-python==1.2.5  # GPL License