Align java version in pom and publish workflow

Align the java version in the pom and the publish workflow.

Author: mcoats13

.github/workflows/publish.yml

@@ -9,20 +9,20 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 11
+      - name: Set up JDK 1.8
         uses: actions/setup-java@v2
         with:
-          distribution: 'temurin'
-          java-version: '11'
+          distribution: 'adopt'
+          java-version: '8'
 
       - name: Build with Maven
         run: mvn -B package --file pom.xml
 
       - name: Set up Maven Central
         uses: actions/setup-java@v2
         with:
-          distribution: 'temurin'
-          java-version: '11'
+          distribution: 'adopt'
+          java-version: '8'
           server-id: ossrh
           server-username: MAVEN_USERNAME
           server-password: MAVEN_PASSWORD

pom.xml

@@ -295,7 +295,7 @@ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/ma
     </dependency>
   </dependencies>
   <properties>
-    <java.version>1.7</java.version>
+    <java.version>1.8</java.version>
     <maven.compiler.source>${java.version}</maven.compiler.source>
     <maven.compiler.target>${java.version}</maven.compiler.target>
     <gson-fire-version>1.8.5</gson-fire-version>