implement sonatype staging plugin for releases. (#128)

pom.xml

@@ -61,7 +61,7 @@
         <com.capitalone.dashboard.core.version>3.6.3</com.capitalone.dashboard.core.version>
         <apache.rat.plugin.version>0.13</apache.rat.plugin.version>
         <coveralls.maven.plugin.version>4.3.0</coveralls.maven.plugin.version>
-        <guava.version>18.0</guava.version>
+        <guava.version>19.0</guava.version>
         <hamcrest.version>1.3</hamcrest.version>
         <jacoco.maven.plugin.version>0.8.3</jacoco.maven.plugin.version>
         <jacoco.coverage.percentage.minimum>0.200</jacoco.coverage.percentage.minimum>
@@ -301,6 +301,12 @@
             <artifactId>gson</artifactId>
             <version>2.8.2</version>
         </dependency>
+        <!-- release to ossrh -->
+        <dependency>
+            <groupId>org.sonatype.plugins</groupId>
+            <artifactId>nexus-staging-maven-plugin</artifactId>
+            <version>1.6.8</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -773,6 +779,19 @@
                             <target>1.8</target>
                         </configuration>
                     </plugin>
+                    <plugin>
+                        <groupId>org.sonatype.plugins</groupId>
+                        <artifactId>nexus-staging-maven-plugin</artifactId>
+                        <version>1.6.8</version>
+                        <extensions>true</extensions>
+                        <configuration>
+                            <serverId>ossrh</serverId>
+                            <nexusUrl>https://oss.sonatype.org/</nexusUrl>
+                            <autoReleaseAfterClose>false</autoReleaseAfterClose>
+                            <!--<autoDropAfterRelease>true</autoDropAfterRelease>-->
+                            <stagingProfileId>26a9600c05a6d3</stagingProfileId>
+                        </configuration>
+                    </plugin>
                     <plugin>
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-source-plugin</artifactId>