Update CI builds to avoid false negatives

Author: whitfin

.travis.yml

@@ -2,6 +2,7 @@ language: elixir
 os:
   - linux
 elixir:
+  - 1.9
   - 1.8
   - 1.7
   - 1.6
@@ -10,26 +11,31 @@ elixir:
   - 1.3
   - 1.2
 otp_release:
-  - 21.2
+  - 22.0
+  - 21.3
   - 20.3
   - 19.3
   - 18.3
 env:
 matrix:
   include:
-    - elixir: 1.8
-      otp_release: 21.2
+    - elixir: 1.9
+      otp_release: 22.0
       script:
         - MIX_ENV=cover mix coveralls.travis --trace
-    - elixir: 1.8
-      otp_release: 21.2
+    - elixir: 1.9
+      otp_release: 22.0
       script:
         - mix credo --all --format=oneline
-    - elixir: 1.8
-      otp_release: 21.2
+    - elixir: 1.9
+      otp_release: 22.0
       script:
         - mix bench
   exclude:
+    - elixir: 1.9
+      otp_release: 19.3
+    - elixir: 1.9
+      otp_release: 18.3
     - elixir: 1.8
       otp_release: 19.3
     - elixir: 1.8
@@ -40,16 +46,24 @@ matrix:
       otp_release: 18.3
     - elixir: 1.5
       otp_release: 21.2
+    - elixir: 1.5
+      otp_release: 18.3
     - elixir: 1.4
       otp_release: 21.2
+    - elixir: 1.4
+      otp_release: 18.3
     - elixir: 1.3
       otp_release: 21.2
     - elixir: 1.3
       otp_release: 20.3
+    - elixir: 1.3
+      otp_release: 18.3
     - elixir: 1.2
       otp_release: 21.2
     - elixir: 1.2
       otp_release: 20.3
+    - elixir: 1.2
+      otp_release: 18.3
   allow_failures:
     - elixir: 1.8
       otp_release: 21.2