No need to keep old and used Travis config file

If we ever want to come back to Travis we just need to do a git revert.
Meanwhile, no need to care about it.

.travis.yml

@@ -1,60 +0,0 @@
-language: ruby
-sudo: false
-cache: bundler
-bundler_args: --without development
-rvm:
-  - "2.1.5"
-addons:
-  postgresql: "9.5"
-
-# Set the timezone for phantomjs with TZ
-# Set the timezone for karma with TIMEZONE
-env:
-  global:
-    - TZ="Australia/Melbourne"
-    - TIMEZONE="Australia/Melbourne"
-    - CI_NODE_TOTAL=5
-  matrix:
-    - CI_NODE_INDEX=0
-    - CI_NODE_INDEX=1
-    - CI_NODE_INDEX=2
-    - CI_NODE_INDEX=3 RSPEC_ENGINES="true"
-    - CI_NODE_INDEX=4 KARMA="true" GITHUB_DEPLOY="true"
-
-before_script:
-  - cp config/database.travis.yml config/database.yml
-  - cp config/application.yml.example config/application.yml
-  - RAILS_ENV=test bundle exec rake db:create db:schema:load
-
-  # Only install PhantomJS if it is not already present (ie. cached)
-  - npm list -g phantomjs-prebuilt@~2.1.7 --depth=0 || npm install -g phantomjs-prebuilt@~2.1.7
-  - export PATH=`npm bin -g`:$PATH
-
-  - >
-    if [ "$KARMA" = "true" ]; then
-      npm install -g npm@'3.8.8'
-      npm install
-      npm install -g karma-cli@0.1.2
-    fi
-
-script:
-  - 'if [ "$KARMA" = "true" ]; then bundle exec rake karma:run; else echo "Skipping karma run"; fi'
-  - 'if [ "$RSPEC_ENGINES" = "true" ]; then bundle exec rake ofn:specs:engines:rspec; else echo "Skipping RSpec run in engines"; fi'
-  - "bundle exec rake 'knapsack:rspec[--format progress --tag ~performance]'"
-
-after_success:
-  - >
-    if [ "$GITHUB_DEPLOY" = "true" -a "$TRAVIS_PULL_REQUEST" = "false" -a -n "$TRAVIS_BRANCH" -a "$TRAVIS_BRANCH" != "transifex" -a -n "$GITHUB_API_SECRET" ]; then
-      description="`git show "$TRAVIS_BRANCH" -s --oneline --no-color`"
-      data="{
-        \"ref\":\"$TRAVIS_BRANCH\",
-        \"description\":\"$description\",
-        \"environment\":\"staging\",
-        \"required_contexts\":[]}"
-      curl -u "$GITHUB_API_SECRET" -d "$data" "https://api.github.com/repos/$TRAVIS_REPO_SLUG/deployments"
-    else
-      echo "Not deploying on this build."
-    fi
-
-notifications:
-  email: false