fixing travis yaml

Author: zookzook

.travis.yml

@@ -1,15 +1,13 @@
 sudo: required
 language: elixir
 
-elixir:
-  - '1.10.2'
-otp_release:
-  - '22'
+elixir: 1.10.2
+otp_release: 22.0
 
 install:
-  - wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1804-4.4.0-rc0.tgz
+  - wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1604-4.4.0-rc0.tgz
   - mkdir ${PWD}/mongodb
-  - tar xzf https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1804-4.4.0-rc0.tgz --strip-components=1 -C ${PWD}/mongodb
+  - tar xzf https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1604-4.4.0-rc0.tgz --strip-components=1 -C ${PWD}/mongodb
 
 before_script:
   - pip3 install mtools[all]