Officially support Ruby 2.6.0

.travis.yml

@@ -13,6 +13,7 @@ env:
   - DATABASE_ADAPTER=postgresql
 
 rvm:
+  - 2.6.0
   - 2.5.1
   - 2.4.4
   - 2.3.7
@@ -22,3 +23,8 @@ gemfile:
   - gemfiles/5.0.gemfile
   - gemfiles/5.1.gemfile
   - gemfiles/5.2.gemfile
+
+matrix:
+  exclude:
+    - rvm: 2.6.0
+      gemfile: gemfiles/4.2.gemfile

NEWS.md

@@ -4,7 +4,7 @@ This release mainly brings the gem up to date with modern versions of Ruby and
 Rails and drops support for older, unsupported versions. The compatibility list
 is now:
 
-* **Ruby:** 2.5.1, 2.4.4, 2.3.7
+* **Ruby:** 2.6.0, 2.5.1, 2.4.4, 2.3.7
 * **Rails:** 5.2.1, 5.1.6, 5.0.6, 4.2.9
 
 ### Backward-incompatible changes