Bump to GitBucket 4.16.0

Author: takezoe

README.MD

@@ -16,6 +16,7 @@ It is then possible, for example, to notify every user that an upgrade of the sy
 
 Plugin version | GitBucket version
 :--------------|:-----------------
+1.7.x          | 4.16.y
 1.6.x          | 4.10.y
 1.5.x          | 4.3.y
 1.4.x          | 4.0.0 -> 4.2.x

build.sbt

@@ -10,7 +10,7 @@ version := ProjectVersion
 scalaVersion := "2.12.2"
 
 libraryDependencies ++= Seq(
-  "io.github.gitbucket"   %% "gitbucket"            % "4.13.0"  % "provided",
+  "io.github.gitbucket"   %% "gitbucket"            % "4.16.0"  % "provided",
   "io.github.gitbucket"   % "solidbase"             % "1.0.2"   % "provided",
   "com.typesafe.play"     %% "twirl-compiler"       % "1.3.0"   % "provided",
   "org.apache.commons"    % "commons-email"         % "1.4"     % "provided",