.travis.yml in cose-0.9.0 vs .travis.yml in cose-0.10.0

@@ -1,15 +1,15 @@
-sudo: false
+dist: bionic
 language: ruby
 cache: bundler
 
 rvm:
   - ruby-head
-  - 2.7.0-preview1
-  - 2.6.4
-  - 2.5.6
-  - 2.4.7
+  - 2.7.0-preview3
+  - 2.6.5
+  - 2.5.7
+  - 2.4.9
   - 2.3.8
 
 gemfile:
   - gemfiles/openssl_head.gemfile
   - gemfiles/openssl_2_1.gemfile
@@ -20,7 +20,6 @@
 
 matrix:
   fast_finish: true
   allow_failures:
     - rvm: ruby-head
-    - rvm: 2.7.0-preview1
     - gemfile: gemfiles/openssl_head.gemfile