Configure default role to include edgelambda

This patch configures a default lambda role matching what SAM provides
in the default role except it also adds edgelambda in the trusted
relationships so that there is no need to perform an additional
manual step after the fact to include it.

Closes: #3
Signed-off-by: Thanh Ha <zxiiro@gmail.com>

sam.yaml

@@ -13,6 +13,31 @@ Resources:
       Handler: index.handler
       Runtime: nodejs10.x
       Description: 'Standard Redirects for CloudFront by Digital Sailors via the Serverless Application Repository.'
+      Role: !GetAtt LambdaRole.Arn
       MemorySize: 128
       Timeout: 3
       AutoPublishAlias: 'CurrentProd'
+
+  LambdaRole:
+    Type: AWS::IAM::Role
+    Properties:
+      AssumeRolePolicyDocument:
+        Version: '2012-10-17'
+        Statement:
+          Effect: Allow
+          Principal:
+            Service:
+              - lambda.amazonaws.com
+              - edgelambda.amazonaws.com
+          Action: sts:AssumeRole
+      Policies:
+        - PolicyName: edgelambda-policy
+          PolicyDocument:
+            Version: "2012-10-17"
+            Statement:
+              - Effect: Allow
+                Action:
+                  - logs:CreateLogGroup
+                  - logs:CreateLogStream
+                  - logs:PutLogEvents
+                Resource: '*'