Explicitly declare dependencies (#54)

* declare dependencies explicitly
diff --git a/archetype-common/pom.xml b/archetype-common/pom.xml
index 1db8766..7dcb9af 100644
--- a/archetype-common/pom.xml
+++ b/archetype-common/pom.xml
@@ -105,6 +105,12 @@
       <artifactId>maven-invoker</artifactId>
     </dependency>
     <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-aether-provider</artifactId>
+      <version>3.0</version>
+      <scope>runtime</scope>
+    </dependency>
+    <dependency>
       <groupId>org.apache.maven.shared</groupId>
       <artifactId>maven-artifact-transfer</artifactId>
     </dependency>
@@ -117,6 +123,15 @@
       <artifactId>commons-io</artifactId>
     </dependency>
     <dependency>
+      <groupId>commons-collections</groupId>
+      <artifactId>commons-collections</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.sonatype.aether</groupId>
+      <artifactId>aether-impl</artifactId>
+      <version>1.7</version>
+    </dependency>
+    <dependency>
       <groupId>org.codehaus.plexus</groupId>
       <artifactId>plexus-velocity</artifactId>
     </dependency>