update samples to gradle 6.8.1

modules/openapi-generator/src/main/resources/kotlin-client/build.gradle.mustache

@@ -2,7 +2,7 @@ group '{{groupId}}'
 version '{{artifactVersion}}'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-gson/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-jackson/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-json-request-string/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-jvm-okhttp4-coroutines/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-moshi-codegen/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-nonpublic/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-nullable/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-okhttp3/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-retrofit2-rx3/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-retrofit2/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-string/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin-threetenbp/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }
 

samples/client/petstore/kotlin/build.gradle

@@ -2,7 +2,7 @@ group 'org.openapitools'
 version '1.0.0'
 
 wrapper {
-    gradleVersion = '4.9'
+    gradleVersion = '6.8.1'
     distributionUrl = "https://services.gradle.org/distributions/gradle-$gradleVersion-all.zip"
 }