GGH-431 Fixed discovery of a start class

- Ensured that FunctionClassUtils performs additional check to ensure that located star class is SpringBootApplication
- Added additional lookup to look for Main-Class if nothing was found in Start-Class primarily to support Azure
- Updated Azure samples
- Updated documentation

Resolves #431

spring-cloud-function-samples/function-sample-azure/src/main/azure/host.json

@@ -1,3 +1,4 @@
 {
-	"functionTimeout": "00:10:00"
+	"functionTimeout": "00:05:00",
+	"version": "2.0"
 }

spring-cloud-function-samples/function-sample-azure/src/main/java/example/Config.java

@@ -22,7 +22,6 @@ import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.annotation.Bean;
 
-// @checkstyle:off
 @SpringBootApplication
 public class Config {
 
@@ -36,7 +35,6 @@ public class Config {
 	}
 
 }
-// @checkstyle:on
 
 class Foo {
 

spring-cloud-function-samples/function-sample-azure/src/main/java/example/FooHandler.java

@@ -18,10 +18,13 @@ package example;
 
 import com.microsoft.azure.functions.ExecutionContext;
 import com.microsoft.azure.functions.HttpMethod;
+import com.microsoft.azure.functions.HttpRequestMessage;
 import com.microsoft.azure.functions.annotation.AuthorizationLevel;
 import com.microsoft.azure.functions.annotation.FunctionName;
 import com.microsoft.azure.functions.annotation.HttpTrigger;
 
+import java.util.Optional;
+
 import org.springframework.cloud.function.adapter.azure.AzureSpringBootRequestHandler;
 
 /**
@@ -30,11 +33,10 @@ import org.springframework.cloud.function.adapter.azure.AzureSpringBootRequestHa
 public class FooHandler extends AzureSpringBootRequestHandler<Foo, Bar> {
 
 	@FunctionName("uppercase")
-	public Bar execute(
-		@HttpTrigger(name = "req", methods = {HttpMethod.GET,
-			HttpMethod.POST}, authLevel = AuthorizationLevel.ANONYMOUS) Foo foo,
+	public Bar execute(@HttpTrigger(name = "req", methods = {HttpMethod.GET,
+			HttpMethod.POST}, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Optional<Foo>> request,
 		ExecutionContext context) {
-		return handleRequest(foo, context);
+		return handleRequest(request.getBody().get(), context);
 	}
 
 }