Automate iOS release (#445)

Summary:
This PR sets up Circle CI to publish pods when github release is made. This PR also updates the Flipper-Folly pod as it didn't build on 32 bit architecture, because `thread_local` was not supported.

Automated publish of cocoapods through Circle CI.
Pull Request resolved: https://github.com/facebook/flipper/pull/445

Reviewed By: danielbuechele

Differential Revision: D15333975

Pulled By: priteshrnandgaonkar

fbshipit-source-id: 7db68efeeebbe344213917f10f9f3ce4132e8cbc

.circleci/config.yml

@@ -20,7 +20,6 @@ jobs:
           command: |
             yes | sdkmanager "platforms;android-27" || true
             ./gradlew :android:assembleRelease && scripts/publish-android-snapshot.sh
-
   release:
     executor: default-executor
     docker:
@@ -32,6 +31,24 @@ jobs:
           command: |
             yes | sdkmanager "platforms;android-27" || true
             ./gradlew :android:assembleRelease && scripts/publish-android-release.sh
+  publish-pods:
+    macos:
+      xcode: "10.2.1"
+    steps:
+      - checkout
+      - run: curl https://cocoapods-specs.circleci.com/fetch-cocoapods-repo-from-s3.sh | bash -s cf
+      - run:
+          name: "Pod version"
+          command: |
+            pod --version
+      - run:
+          name: "Push Flipper Pod"
+          command: |
+            pod trunk push ./Flipper.podspec --use-libraries --allow-warnings --verbose --skip-import-validation
+      - run:
+          name: "Push FlipperKit Pod"
+          command: |
+            pod trunk push ./FlipperKit.podspec --use-libraries --allow-warnings --verbose --skip-import-validation --swift-version=4.2
 
 workflows:
   version: 2
@@ -47,3 +64,9 @@ workflows:
               only: /^v.*/
             branches:
               ignore: /.*/
+      - publish-pods:
+          filters:
+            tags:
+              only: /^v.*/
+            branches:
+              ignore: /.*/