feat(deps): adopt flatten plugin and google-cloud-shared-dependencies (#223)

Author: yangnuoyu

.gitignore

@@ -14,4 +14,4 @@ target/
 *.pyc
 __pycache__
 
-.flattened-pom.xml
+.flattened-pom.xml

pom.xml

@@ -196,7 +196,7 @@
             <link>https://developers.google.com/protocol-buffers/docs/reference/java/</link>
             <link>https://googleapis.dev/java/google-auth-library/latest/</link>
             <link>https://googleapis.dev/java/gax/latest/</link>
-            <link>https://googleapis.github.io/api-common-java/${google.api-common.version}/apidocs/</link>
+            <link>https://googleapis.github.io/api-common-java/</link>
           </links>
         </configuration>
       </plugin>