Update master.yml

Author: AB-xdev

.github/workflows/master.yml

@@ -13,7 +13,8 @@ jobs:
     - name: Set up JDK 1.8
       uses: actions/setup-java@v2
       with:
-        java-version: 1.8
+        java-version: '8'
+        distribution: 'adopt'
 
     - name: Cache local Maven repository
       uses: actions/cache@v2
@@ -119,7 +120,8 @@ jobs:
     - name: Set up JDK 1.8 Apache Maven Central
       uses: actions/setup-java@v2
       with: # running setup-java again overwrites the settings.xml
-        java-version: 1.8
+        java-version: '8'
+        distribution: 'adopt'
         server-id: ossrh
         server-username: MAVEN_CENTRAL_USERNAME
         server-password: MAVEN_CENTRAL_TOKEN
@@ -149,7 +151,8 @@ jobs:
     - name: Set up JDK 1.8
       uses: actions/setup-java@v2
       with:
-        java-version: 1.8
+        java-version: '8'
+        distribution: 'adopt'
 
     - name: Build for Vaadin Directory
       run: mvn -B install -Pdirectory
@@ -194,7 +197,8 @@ jobs:
     - name: Setup - Java
       uses: actions/setup-java@v2
       with:
-        java-version: 1.8
+        java-version: '8'
+        distribution: 'adopt'
 
     - name: Restore - Maven Cache
       uses: actions/cache@v1