Speed improvement for builds without DB

Now the builds which do not use the DB or Redis won't pull the images
from docker, and won't migrate the DB. This _should_ improve the build
times slightly but also create a cleaner trace.

.gitlab-ci.yml

 image: "ruby:2.1"
 
-services:
-  - mysql:latest
-  - redis:alpine
-
 cache:
   key: "ruby21"
   paths:
@@ -34,7 +30,6 @@ stages:
 - post-test
 
 # Prepare and merge knapsack tests
-
 .knapsack-state: &knapsack-state
   services: []
   variables:
@@ -70,6 +65,9 @@ update-knapsack:
 
 .rspec-knapsack: &rspec-knapsack
   stage: test
+  services:
+    - mysql:latest
+    - redis:alpine
   script:
     - bundle exec rake assets:precompile 2>/dev/null
     - JOB_NAME=( $CI_BUILD_NAME )
@@ -85,6 +83,9 @@ update-knapsack:
 
 .spinach-knapsack: &spinach-knapsack
   stage: test
+  services:
+    - mysql:latest
+    - redis:alpine
   script:
     - bundle exec rake assets:precompile 2>/dev/null
     - JOB_NAME=( $CI_BUILD_NAME )
@@ -133,6 +134,9 @@ spinach 9 10: *spinach-knapsack
 # Execute all testing suites against Ruby 2.3
 .ruby-23: &ruby-23
   image: "ruby:2.3"
+  services:
+    - mysql:latest
+    - redis:alpine
   only:
     - master
   cache:
@@ -148,7 +152,7 @@ spinach 9 10: *spinach-knapsack
 .spinach-knapsack-ruby23: &spinach-knapsack-ruby23
   <<: *spinach-knapsack
   <<: *ruby-23
-  
+
 rspec 0 20 ruby23: *rspec-knapsack-ruby23
 rspec 1 20 ruby23: *rspec-knapsack-ruby23
 rspec 2 20 ruby23: *rspec-knapsack-ruby23
@@ -184,21 +188,43 @@ spinach 9 10 ruby23: *spinach-knapsack-ruby23
 # Other generic tests
 
 .exec: &exec
+  variables:
+    SIMPLECOV: "false"
+    USE_DB: "false"
+    USE_BUNDLE_INSTALL: "true"
   stage: test
   script:
     - bundle exec $CI_BUILD_NAME
 
-teaspoon: *exec
 rubocop: *exec
 rake scss_lint: *exec
 rake brakeman: *exec
 rake flog: *exec
 rake flay: *exec
-rake db:migrate:reset: *exec
 license_finder: *exec
 
+rake db:migrate:reset:
+  stage: test
+  services:
+    - mysql:latest
+    - redis:alpine
+  script:
+    - rake db:migrate:reset
+
+teaspoon:
+  stage: test
+  services:
+    - mysql:latest
+    - redis:alpine
+  script:
+    - teaspoon
+
 bundler:audit:
   stage: test
+  variables:
+    SIMPLECOV: "false"
+    USE_DB: "false"
+    USE_BUNDLE_INSTALL: "true"
   only:
     - master
   script: