chore: use Fn::Sub instead of Fn::Join

Author: erezrokah

lib/package/sns/compileMethodsToSns.js

@@ -51,16 +51,7 @@ module.exports = {
         'Fn::GetAtt': ['ApigatewayToSnsRole', 'Arn']
       },
       Uri: {
-        'Fn::Join': [
-          '',
-          [
-            'arn:aws:apigateway:',
-            {
-              Ref: 'AWS::Region'
-            },
-            ':sns:path//'
-          ]
-        ]
+        'Fn::Sub': 'arn:aws:apigateway:${AWS::Region}:sns:path//'
       },
       PassthroughBehavior: 'NEVER',
       RequestParameters: {

lib/package/sns/compileMethodsToSns.test.js

@@ -70,7 +70,7 @@ describe('#compileMethodsToSns()', () => {
             Type: 'AWS',
             Credentials: { 'Fn::GetAtt': ['ApigatewayToSnsRole', 'Arn'] },
             Uri: {
-              'Fn::Join': ['', ['arn:aws:apigateway:', { Ref: 'AWS::Region' }, ':sns:path//']]
+              'Fn::Sub': 'arn:aws:apigateway:${AWS::Region}:sns:path//'
             },
             PassthroughBehavior: 'NEVER',
             RequestParameters: {
@@ -196,7 +196,7 @@ describe('#compileMethodsToSns()', () => {
             Type: 'AWS',
             Credentials: { 'Fn::GetAtt': ['ApigatewayToSnsRole', 'Arn'] },
             Uri: {
-              'Fn::Join': ['', ['arn:aws:apigateway:', { Ref: 'AWS::Region' }, ':sns:path//']]
+              'Fn::Sub': 'arn:aws:apigateway:${AWS::Region}:sns:path//'
             },
             PassthroughBehavior: 'NEVER',
             RequestParameters: {
@@ -465,7 +465,7 @@ describe('#compileMethodsToSns()', () => {
             Type: 'AWS',
             Credentials: { 'Fn::GetAtt': ['ApigatewayToSnsRole', 'Arn'] },
             Uri: {
-              'Fn::Join': ['', ['arn:aws:apigateway:', { Ref: 'AWS::Region' }, ':sns:path//']]
+              'Fn::Sub': 'arn:aws:apigateway:${AWS::Region}:sns:path//'
             },
             PassthroughBehavior: 'NEVER',
             RequestParameters: {
@@ -578,7 +578,7 @@ describe('#compileMethodsToSns()', () => {
             Type: 'AWS',
             Credentials: { 'Fn::GetAtt': ['ApigatewayToSnsRole', 'Arn'] },
             Uri: {
-              'Fn::Join': ['', ['arn:aws:apigateway:', { Ref: 'AWS::Region' }, ':sns:path//']]
+              'Fn::Sub': 'arn:aws:apigateway:${AWS::Region}:sns:path//'
             },
             PassthroughBehavior: 'NEVER',
             RequestParameters: {