Revert "Try GH actions instead of travis"

This reverts commit 6ac426e.

.travis.yml

@@ -0,0 +1,30 @@
+language: r
+
+r:
+  - bioc-devel
+  - bioc-release
+
+# Strict checks in place
+warnings_are_errors: false
+
+cache:
+  - packages: true
+
+#branches:
+#  only:
+#    - master
+before_install:
+  - sudo apt-get -y install libmagick++-dev
+
+r_github_packages:
+  - jimhester/covr
+
+notifications:
+  email:
+    recipients:
+      - cvallejos@turing.ac.uk 
+    on_success: change # default: change
+    on_failure: always # default: always
+
+after_success:
+  - Rscript -e 'library(covr); codecov()'