Update travis

.travis.yml

@@ -1,16 +1,24 @@
 language: erlang
 
-before_install:
-  - curl https://sh.rustup.rs -sSf | sh -s -- -y
+matrix:
+  include:
+    - os: linux
+      dist: xenial
+      otp_release: 21.3
+    - os: linux
+      dist: xenial
+      otp_release: 22.0
+    - os: osx
+      language: generic
+
+before_script:
+- curl https://sh.rustup.rs -sSf | sh -s -- -y
+- if [[ $TRAVIS_OS_NAME == linux ]]; then sudo apt-get -y update || true ; fi
+- if [[ $TRAVIS_OS_NAME == linux ]]; then sudo apt-get install -y g++ make cmake libssl-dev libuv1-dev || true ; fi
+- if [[ $TRAVIS_OS_NAME == osx ]]; then brew update; fi
+- if [[ $TRAVIS_OS_NAME == osx ]]; then brew install erlang || true; fi
+- curl https://s3.amazonaws.com/rebar3/rebar3 --output rebar3 && chmod +x rebar3
 
 script:
   - source $HOME/.cargo/env
-  - rebar3 eunit
-
-otp_release:
-  - 21.3
-  - 22.0
-
-os:
-  - linux
-  - osx
+  - ./rebar3 eunit