fix travis mongodb integration

.ci/travis-before-script.sh

@@ -4,6 +4,9 @@ set -e -x
 
 if [[ "${TOXENV}" == *-rdb ]]; then
     rethinkdb --daemon
-elif [[ "${TOXENV}" == *-mdb ]]; then
-    sudo service mongod start
+elif [[ "${BIGCHAINDB_DATABASE_BACKEND}" == mongodb ]]; then
+    wget http://downloads.mongodb.org/linux/mongodb-linux-x86_64-3.4.1.tgz -O /tmp/mongodb.tgz
+    tar -xvf /tmp/mongodb.tgz
+    mkdir /tmp/mongodb-data
+    ${PWD}/mongodb-linux-x86_64-3.4.1/bin/mongod --dbpath=/tmp/mongodb-data --replSet=rs0 &
 fi

.ci/travis_script.sh

@@ -4,6 +4,8 @@ set -e -x
 
 if [[ -n ${TOXENV} ]]; then
   tox -e ${TOXENV}
+elif [[ "${BIGCHAINDB_DATABASE_BACKEND}" == mongodb ]]; then
+    pytest -vs --database-backend=mongodb --cov=bigchaindb
 else
   pytest -v -n auto --cov=bigchaindb
 fi

.travis.yml

@@ -27,7 +27,6 @@ matrix:
       rethinkdb: '2.3.5'
     env: BIGCHAINDB_DATABASE_BACKEND=rethinkdb
   - python: 3.5
-    services: mongodb
     env: BIGCHAINDB_DATABASE_BACKEND=mongodb
   - python: 3.5
     addons: 
@@ -38,6 +37,8 @@ before_install: sudo .ci/travis-before-install.sh
 
 install: .ci/travis-install.sh
 
+before_script: .ci/travis-before-script.sh
+
 script: .ci/travis_script.sh
 
 after_success: .ci/travis-after-success.sh