Fixed explain tests

Updated travis.yml to support replicasets

.travis.yml

@@ -9,6 +9,34 @@ services:
   - docker
 
 env:
+  DOCKER_COMPOSE_VERSION: 1.8.0
+  TEST_MONGODB_FLAVOR: mongo
+  TEST_PSMDB_VERSION: 4.0
+  TEST_MONGODB_ADMIN_USERNAME: admin
+  TEST_MONGODB_ADMIN_PASSWORD: admin123456
+  TEST_MONGODB_USERNAME: test
+  TEST_MONGODB_PASSWORD: 123456
+  TEST_MONGODB_STANDALONE_PORT: 27017
+  TEST_MONGODB_MONGOS_PORT: 17000
+  TEST_MONGODB_S1_RS: rs1
+  TEST_MONGODB_S1_PRIMARY_PORT: 17001
+  TEST_MONGODB_S1_SECONDARY1_PORT: 17002
+  TEST_MONGODB_S1_SECONDARY2_PORT: 17003
+  TEST_MONGODB_S2_RS: rs2
+  TEST_MONGODB_S2_PRIMARY_PORT: 17004
+  TEST_MONGODB_S2_SECONDARY1_PORT: 17005
+  TEST_MONGODB_S2_SECONDARY2_PORT: 17006
+  TEST_MONGODB_CONFIGSVR_RS: csReplSet
+  TEST_MONGODB_CONFIGSVR1_PORT: 17007
+  TEST_MONGODB_CONFIGSVR2_PORT: 17008
+  TEST_MONGODB_CONFIGSVR3_PORT: 17009
+  TEST_MONGODB_S3_RS: rs3
+  TEST_MONGODB_S3_PRIMARY_PORT: 17021
+  TEST_MONGODB_S3_SECONDARY1_PORT: 17022
+  TEST_MONGODB_S3_SECONDARY2_PORT: 17023
+  MINIO_ENDPOINT: http://localhost:9000/
+  MINIO_ACCESS_KEY_ID: example00000
+  MINIO_SECRET_ACCESS_KEY: secret00000
   matrix:
     - MONGODB_IMAGE=mongo:3.0
     - MONGODB_IMAGE=mongo:3.2
@@ -17,6 +45,11 @@ env:
     - MONGODB_IMAGE=percona/percona-server-mongodb:3.2
     - MONGODB_IMAGE=percona/percona-server-mongodb:3.4
 
+before_install:
+    - sudo apt-get update
+    - sudo apt-get install -o Dpkg::Options::="--force-confold" --force-yes -y docker-engine
+    - docker-compose --version
+
 install:
   - go get -u github.com/golang/dep/cmd/dep