Change circleci configuration to only release on tags

Setup circleci dependency caching

Author: rdbatch

.circleci/config.yml

@@ -1,18 +1,54 @@
 version: 2
 jobs:
   build:
-    working_directory: /kotlin-native-lambda-runtime
+    working_directory: ~/kotlin-native-lambda-runtime
     docker:
       - image: c1phr/kotlin-native-lambda-runtime-compiler:latest
     steps:
       - checkout
+      - restore_cache:
+          key: deps-{{ checksum "build.gradle" }}
       - run:
           name: Build runtime
           command: |
             ./gradlew clean build linuxTest
+      - save_cache: # saves the project dependencies
+          paths:
+            - ~/.gradle
+          key: deps-{{ checksum "build.gradle" }}
+      - persist_to_workspace:
+          root: .
+          paths:
+            - .
+  deploy:
+    working_directory: ~/kotlin-native-lambda-runtime
+    docker:
+      - image: c1phr/kotlin-native-lambda-runtime-compiler:latest
+    steps:
+      - attach_workspace:
+          at: .
       - deploy:
           name: Publish to Bintray
-          command: |
-            if [ "${CIRCLE_BRANCH}" == "master" ]; then
-              ./gradlew generatePomFileForKotlinMultiplatformPublication generateMetadataFileForKotlinMultiplatformPublication bintrayUpload bintrayPublish -PbuildNum="1.0.${CIRCLE_BUILD_NUM}"
-            fi
+          command: ./gradlew generatePomFileForKotlinMultiplatformPublication generateMetadataFileForKotlinMultiplatformPublication bintrayUpload bintrayPublish -PbuildNum="${CIRCLE_TAG}"
+
+workflows:
+  version: 2
+  build:
+    jobs:
+      - build
+  release:
+    jobs:
+      - build:
+          filters:
+            branches:
+              ignore: /.*/
+            tags:
+              only: /^\d+\.\d+\.\d+$/
+      - deploy:
+          requires:
+            - build
+          filters:
+            branches:
+              only: master
+            tags:
+              only: /^\d+\.\d+\.\d+$/