Combine cucumber and cucumber:boot into one job

MSP-11671

The run times for cucumber are so much faster now that `spec --tag
content` is actually the slowest job (on 1.9.3).  The job is so slow
that the two cucumbers can be merged together and they will take the
same time, but we'll consume 2 fewer job slots (1 for 1.9.3 and 1 for
2.1), so the longer per job time is better as long as it does become the
longest job time.

Author: limhoff-r7

.travis.yml

@@ -1,9 +1,8 @@
 bundler_args: --without development coverage
 env:
-  - RAKE_TASK=cucumber
-  - RAKE_TASK=cucumber:boot
-  - RAKE_TASK=spec SPEC_OPTS="--tag content"
-  - RAKE_TASK=spec SPEC_OPTS="--tag ~content"
+  - RAKE_TASKS="cucumber cucumber:boot"
+  - RAKE_TASKS=spec SPEC_OPTS="--tag content"
+  - RAKE_TASKS=spec SPEC_OPTS="--tag ~content"
 
 language: ruby
 matrix:
@@ -26,7 +25,7 @@ before_script:
   - bundle exec rake db:migrate
 script:
   # fail build if db/schema.rb update is not committed
-  - git diff --exit-code && bundle exec rake $RAKE_TASK
+  - git diff --exit-code && bundle exec rake $RAKE_TASKS
 
 rvm:
   - '1.9.3'