added info on nodejs8.10

Based on https://aws.amazon.com/blogs/compute/node-js-8-10-runtime-now-available-in-aws-lambda/

Author: gojko

doc_source/API_CreateFunction.md

@@ -117,10 +117,10 @@ Required: Yes
 
  ** [Runtime](#API_CreateFunction_RequestSyntax) **   <a name="SSS-CreateFunction-request-Runtime"></a>
 The runtime environment for the Lambda function you are uploading\.  
-To use the Python runtime v3\.6, set the value to "python3\.6"\. To use the Python runtime v2\.7, set the value to "python2\.7"\. To use the Node\.js runtime v6\.10, set the value to "nodejs6\.10"\. To use the Node\.js runtime v4\.3, set the value to "nodejs4\.3"\. To use the \.NET Core runtime v1\.0, set the value to "dotnetcore1\.0"\. To use the \.NET Core runtime v2\.0, set the value to "dotnetcore2\.0"\.  
+To use the Python runtime v3\.6, set the value to "python3\.6"\. To use the Python runtime v2\.7, set the value to "python2\.7"\. To use the Node\.js runtime v8\.10, set the value to "nodejs8\.10"\. To use the Node\.js runtime v6\.10, set the value to "nodejs6\.10"\. To use the Node\.js runtime v4\.3, set the value to "nodejs4\.3"\. To use the \.NET Core runtime v1\.0, set the value to "dotnetcore1\.0"\. To use the \.NET Core runtime v2\.0, set the value to "dotnetcore2\.0"\.  
 Node v0\.10\.42 is currently marked as deprecated\. You must migrate existing functions to the newer Node\.js runtime versions available on AWS Lambda \(nodejs4\.3 or nodejs6\.10\) as soon as possible\. Failure to do so will result in an invalid parameter error being returned\. Note that you will have to follow this procedure for each region that contains functions written in the Node v0\.10\.42 runtime\.
 Type: String  
-Valid Values:` nodejs | nodejs4.3 | nodejs6.10 | java8 | python2.7 | python3.6 | dotnetcore1.0 | dotnetcore2.0 | nodejs4.3-edge | go1.x`   
+Valid Values:` nodejs | nodejs4.3 | nodejs6.10 | nodejs8.10 | java8 | python2.7 | python3.6 | dotnetcore1.0 | dotnetcore2.0 | nodejs4.3-edge | go1.x`   
 Required: Yes
 
  ** [Tags](#API_CreateFunction_RequestSyntax) **   <a name="SSS-CreateFunction-request-Tags"></a>
@@ -331,4 +331,4 @@ For more information about using this API in one of the language\-specific AWS S
 
 +  [AWS SDK for Python](http://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/CreateFunction) 
 
-+  [AWS SDK for Ruby V2](http://docs.aws.amazon.com/goto/SdkForRubyV2/lambda-2015-03-31/CreateFunction) 
++  [AWS SDK for Ruby V2](http://docs.aws.amazon.com/goto/SdkForRubyV2/lambda-2015-03-31/CreateFunction)