Change the tag format from ruby2.5Action to 2.5 (#22)

diff --git a/.travis.yml b/.travis.yml
index 4909a5f..0aa6c42 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,12 +22,7 @@
     all_branches: true
     repo: apache/incubator-openwhisk-runtime-ruby
 - provider: script
-  script: "./tools/travis/publish.sh openwhisk ruby2.5Action  latest"
-  on:
-    branch: master
-    repo: apache/incubator-openwhisk-runtime-ruby
-- provider: script
-  script: "./tools/travis/publish.sh openwhisk ruby2.6ActionLoop latest"
+  script: "./tools/travis/publish.sh openwhisk 2.5 latest && ./tools/travis/publish.sh openwhisk 2.6 latest"
   on:
     branch: master
     repo: apache/incubator-openwhisk-runtime-ruby
diff --git a/tools/travis/publish.sh b/tools/travis/publish.sh
index 9e66d40..4d0330b 100755
--- a/tools/travis/publish.sh
+++ b/tools/travis/publish.sh
@@ -27,13 +27,19 @@
 export OPENWHISK_HOME=$WHISKDIR
 
 IMAGE_PREFIX=$1
-RUNTIME=$2
+RUNTIME_VERSION=$2
 IMAGE_TAG=$3
 
 if [[ ! -z ${DOCKER_USER} ]] && [[ ! -z ${DOCKER_PASSWORD} ]]; then
 docker login -u "${DOCKER_USER}" -p "${DOCKER_PASSWORD}"
 fi
 
+if [ ${RUNTIME_VERSION} == "2.5" ]; then
+  RUNTIME="ruby2.5Action"
+elif [ ${RUNTIME_VERSION} == "2.6" ]; then
+  RUNTIME="ruby2.6ActionLoop"
+fi
+
 if [[ ! -z ${RUNTIME} ]]; then
 TERM=dumb ./gradlew \
 :core:${RUNTIME}:distDocker \