Fix issue zeromq#197 - Only sign artifacts when it's time to release

Author: Trevor Bernard

pom.xml

@@ -146,6 +146,32 @@
                 </snapshotRepository>
             </distributionManagement>
         </profile>
+        <profile>
+            <id>release-sign-artifacts</id>
+            <activation>
+                <property>
+                    <name>performRelease</name>
+                    <value>true</value>
+                </property>
+            </activation>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-gpg-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <id>sign-artifacts</id>
+                                <phase>verify</phase>
+                                <goals>
+                                    <goal>sign</goal>
+                                </goals>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
     </profiles>
     <dependencies>
         <dependency>
@@ -159,19 +185,6 @@
         <sourceDirectory>src</sourceDirectory>
         <testSourceDirectory>test/src</testSourceDirectory>
         <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-gpg-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <id>sign-artifacts</id>
-                        <phase>verify</phase>
-                        <goals>
-                            <goal>sign</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
             <plugin>
 	        <artifactId>maven-assembly-plugin</artifactId>
 	        <version>${maven-assembly-plugin.version}</version>