Update TFLint to v0.12.1 for circleci (#351)

Update TFLint to v0.12.1

Author: DrFaust92

.circleci/config.yml

@@ -29,7 +29,7 @@ jobs:
           command: if [[ -n "$(terraform fmt -write=false)" ]]; then echo "Some terraform files need be formatted, run 'terraform fmt' to fix"; exit 1; fi
       - run:
           name: Install tflint
-          command: curl -L -o /tmp/tflint.zip https://github.com/wata727/tflint/releases/download/v0.8.2/tflint_linux_amd64.zip && unzip /tmp/tflint.zip -d /usr/local/bin
+          command: curl -L -o /tmp/tflint.zip https://github.com/wata727/tflint/releases/download/v0.12.1/tflint_linux_amd64.zip && unzip /tmp/tflint.zip -d /usr/local/bin
       - run:
           name: Check Terraform configurations with tflint
           command: tflint