Move db migrate on Travis into `install` step.

This will allow us to collapse the migration logs.

.travis.yml

@@ -61,6 +61,7 @@ install:
   - bash -c "if [ '$RAILS_MASTER' == '0' ]; then bundle install --without development --deployment --retry=3 --jobs=3 > /dev/null; fi"
   - bash -c "if [ '$RUN_LINT' == '1' ]; then yarn global add eslint babel-eslint > /dev/null; fi"
   - bash -c "if [ '$QUNIT_RUN' == '1' ]; then yarn install --dev > /dev/null; fi"
+  - bash -c "if [ -z '$RUN_LINT' ]; bundle exec rake db:create db:migrate; fi"
 
 script:
   - |
@@ -73,8 +74,6 @@ script:
         eslint --ext .es6 plugins/**/test/javascripts && \
         eslint app/assets/javascripts test/javascripts
       else
-        bundle exec rake db:create db:migrate
-
         if [ '$QUNIT_RUN' == '1' ]; then
           bundle exec rake qunit:test['500000'] && \
           bundle exec rake plugin:qunit