Install rethinkdb on travis via apt-get

Although the docker setup worked, codecov could not find the report

.travis.yml

@@ -1,14 +1,22 @@
 sudo: required
 language: python
-python: 3.5
-
-services:
-  - docker
+python:
+  - 3.4
+  - 3.5
 
 before_install:
-  - pip install codecov
-  - docker-compose build
+  - source /etc/lsb-release
+  - echo "deb http://download.rethinkdb.com/apt $DISTRIB_CODENAME main" | sudo tee -a /etc/apt/sources.list.d/rethinkdb.list
+  - wget -qO- https://download.rethinkdb.com/apt/pubkey.gpg | sudo apt-key add -
+  - sudo apt-get update -qq
 
-script: docker-compose run --rm bigchaindb py.test -v --cov=bigchaindb
+install:
+  - sudo apt-get install rethinkdb
+  - pip install -e .[test]
+  - pip install codecov
+
+before_script: rethinkdb --daemon
+
+script: py.test -v --cov=bigchaindb
 
 after_success: codecov