core: Update Travis-CI build configuration

Author: ppmathis

.travis.yml

@@ -6,22 +6,23 @@ addons:
     packages:
       - rpm
 
-go:
-  - 1.9.x
-  - 1.10.x
+matrix:
+  include:
+    - go: 1.9.x
+    - go: 1.10.x
+      env: NAGOCHECK_DEPLOY=1
 
 install:
   - make devel-deps
 
 script:
   - make lint
   - make test
-  # TODO: - make coverage
 
 deploy:
   - provider: script
     skip_cleanup: true
     script: curl -sL http://git.io/goreleaser | bash
     on:
       tags: true
-      condition: $TRAVIS_GO_VERSION =~ ^1\.10(\.[0-9]+)?$
+      condition: $NAGOCHECK_DEPLOY = 1