Merge pull request #15 from navarasu/fix_14_preinstall_yums

#14 Implemented option to preinstall yums before bundling gem

Author: navarasu

examples/using_docker/Gemfile renamed to examples/use_docker/Gemfile

@@ -0,0 +1,2 @@
+source 'https://rubygems.org'
+gem 'pg'

examples/using_docker/handler.rb renamed to examples/use_docker/handler.rb

@@ -0,0 +1,8 @@
+require 'pg'
+
+def hello(event:, context:)
+  { statusCode: 200, body: {
+    "pg_version": PG.library_version
+    }
+  }
+end

examples/using_docker/serverless.yml renamed to examples/use_docker/serverless.yml

@@ -0,0 +1,20 @@
+service: using-docker-file 
+
+plugins:
+  - serverless-ruby-layer
+
+custom:
+  rubyLayer:
+    use_docker: true
+    docker_yums:
+      - postgresql-devel
+    native_libs:
+      - /usr/lib64/libpq.so.5
+
+provider:
+  name: aws
+  runtime: ruby2.5
+
+functions:
+  hello:
+    handler: handler.hello