-Fix file format. -Remove default from TraceContext. -Update the object return

-Install only the required plugins to function

build.ps1

@@ -19,10 +19,10 @@ $atchetypeVersion = $matches[1]
 Write-Host "atchetypeVersion: " $atchetypeVersion
 
 # Clone and install function maven plugin
-git clone https://github.com/Microsoft/azure-maven-plugins.git -b master
+git clone https://github.com/Microsoft/azure-maven-plugins.git -b develop
 Push-Location -Path "./azure-maven-plugins" -StackName libraryDir
 Write-Host "Build and install azure-functions-maven-plugins" 
-cmd.exe /c '.\..\mvnBuildSkipTests.bat'
+cmd.exe /c '.\..\mvnBuildFunctionPluginsSkipTests.bat'
 StopOnFailedExecution
 Pop-Location -StackName "libraryDir"
 $pluginPom = Get-Content ".\azure-maven-plugins\azure-functions-maven-plugin\pom.xml" | where {$_ -ne ""} 

mvnBuildFunctionPluginsSkipTests.bat

@@ -0,0 +1 @@
+mvn clean install -pl build-tools,azure-maven-plugins-pom,azure-maven-plugin-lib,azure-functions-maven-plugin -Dmaven.javadoc.skip=true -Dmaven.test.skip -U -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn -B

src/main/java/com/microsoft/azure/functions/ExecutionContext.java

@@ -39,7 +39,8 @@ public interface ExecutionContext {
      * Returns the trace context.
      * @return the trace context
      */
-	default TraceContext getTraceContext() {
-        return new TraceContext(){};
+    default TraceContext getTraceContext() {
+        return null;
     }
 }
+

src/main/java/com/microsoft/azure/functions/TraceContext.java

@@ -6,7 +6,6 @@
 
 package com.microsoft.azure.functions;
 
-import java.util.Collections;
 import java.util.Map;
 
 /**
@@ -20,23 +19,17 @@ public interface TraceContext {
      *
      * @return the TraceparentString from the Activity.
      */
-    default String getTraceparent() {
-        return "";
-    }
+    String getTraceparent();
 
     /**
      * Returns the Tracestate which is Activity.Current?.Id from host.
      * @return the Tracestate which is Activity.Current?.Id from host.
      */
-    default String getTracestate() {
-        return "";
-    }
+    String getTracestate();
 
     /**
      * Returns the attributes which correspond to the tags.
      * @return the attributes which correspond to the tags.
      */
-    default Map<String, String> getAttributes() {
-        return Collections.<String, String>emptyMap();
-    }
-}
+    Map<String, String> getAttributes();
+}