bump Scala 2.12 versions to 2.12.16 (was .15) (#544)

Author: SethTisue

README.md

@@ -49,7 +49,7 @@ And, it includes support for some non-collections classes such as the `@nowarn`
 
 ## Migration rules
 
-The migration rules use scalafix. Please see the [official installation instructions](https://scalacenter.github.io/scalafix/docs/users/installation.html) and, in particular, check that your full Scala version is supported (ex 2.12.15).
+The migration rules use scalafix. Please see the [official installation instructions](https://scalacenter.github.io/scalafix/docs/users/installation.html) and, in particular, check that your full Scala version is supported (ex 2.12.16).
 
 ```scala
 // project/plugins.sbt

build.sbt

@@ -51,7 +51,7 @@ lazy val root = project
 lazy val junit = libraryDependencies += "com.github.sbt" % "junit-interface" % "0.13.3" % Test
 
 lazy val scala211 = "2.11.12"
-lazy val scala212 = "2.12.15"
+lazy val scala212 = "2.12.16"
 lazy val scala213 = "2.13.8"
 lazy val scala30  = "3.0.2"
 lazy val scala31  = "3.1.3"

project/MultiScalaProject.scala

@@ -21,9 +21,9 @@ import java.io.File
  *   _.settings(...) // Project => Project (scala version independent configurations)
  * )
  *
- * // instanciate a sbt project
+ * // instantiate a sbt project
  * lazy val myProject211 = myProject("2.11.12", _.settings(...) /* scala version dependent configurations */)
- * lazy val myProject212 = myProject("2.12.14" , _.settings(...))
+ * lazy val myProject212 = myProject("2.12.16" , _.settings(...))
  * // ...
  * }}}
  */