Build for Java 8; upgrade dependencies and plugins (#27)

Author: sbabcoc

pom.xml

@@ -26,17 +26,17 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <maven.compiler.release>7</maven.compiler.release>
-    <testng.version>6.10</testng.version>
-    <compiler-plugin.version>3.8.1</compiler-plugin.version>
-    <surefire-plugin.version>3.0.0-M5</surefire-plugin.version>
+    <maven.compiler.release>8</maven.compiler.release>
+    <testng.version>7.5</testng.version>
+    <compiler-plugin.version>3.10.1</compiler-plugin.version>
+    <surefire-plugin.version>3.0.0-M7</surefire-plugin.version>
     <source-plugin.version>3.2.1</source-plugin.version>
-    <javadoc-plugin.version>3.3.0</javadoc-plugin.version>
-    <guava-agent.version>30.1.1a</guava-agent.version>
+    <javadoc-plugin.version>3.4.0</javadoc-plugin.version>
+    <guava.version>31.1-jre</guava.version>
     <gpg-plugin.version>3.0.1</gpg-plugin.version>
-    <staging-plugin.version>1.6.8</staging-plugin.version>
-    <release-plugin.version>3.0.0-M4</release-plugin.version>
-    <apache-derby.version>10.12.1.1</apache-derby.version>
+    <staging-plugin.version>1.6.13</staging-plugin.version>
+    <release-plugin.version>3.0.0-M6</release-plugin.version>
+    <apache-derby.version>10.14.2.0</apache-derby.version>
     <skipSigning>true</skipSigning>
   </properties>
 
@@ -71,9 +71,9 @@
         <version>${apache-derby.version}</version>
       </dependency>
       <dependency>
-        <groupId>com.nordstrom.tools</groupId>
-        <artifactId>guava-agent</artifactId>
-        <version>${guava-agent.version}</version>
+        <groupId>com.google.guava</groupId>
+        <artifactId>guava</artifactId>
+        <version>${guava.version}</version>
       </dependency>
     </dependencies>
   </dependencyManagement>
@@ -90,8 +90,8 @@
       <scope>test</scope>
     </dependency>
     <dependency>
-      <groupId>com.nordstrom.tools</groupId>
-      <artifactId>guava-agent</artifactId>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
     </dependency>
   </dependencies>