deprecation warnings for ProcessBuilder#lines in Scala 2.11

[seratch]

[warn] /Users/k-sera/Documents/github/skinny-framework/assets/src/main/scala/skinny/assets/CoffeeScriptCompiler.scala:43: method lines in trait ProcessBuilder is deprecated: Use lineStream instead.
[warn]   private[this] def nativeCompilerDescription = Seq(coffeeCommand, "-v").lines.mkString
[warn]                                                                          ^
[warn] /Users/k-sera/Documents/github/skinny-framework/assets/src/main/scala/skinny/assets/CoffeeScriptCompiler.scala:50: method lines in trait ProcessBuilder is deprecated: Use lineStream instead.
[warn]     try Seq(coffeeCommand, "-v").lines.size > 0
[warn]                                  ^
[warn] /Users/k-sera/Documents/github/skinny-framework/assets/src/main/scala/skinny/assets/LessCompiler.scala:25: method lines in trait ProcessBuilder is deprecated: Use lineStream instead.
[warn]   private[this] def nativeCompilerDescription = Seq(lessCommand, "-v").lines.mkString
[warn]                                                                        ^
[warn] /Users/k-sera/Documents/github/skinny-framework/assets/src/main/scala/skinny/assets/LessCompiler.scala:30: method lines in trait ProcessBuilder is deprecated: Use lineStream instead.
[warn]     try Seq(lessCommand, "-v").lines.size > 0
[warn]                                ^
[warn] /Users/k-sera/Documents/github/skinny-framework/assets/src/main/scala/skinny/assets/ReactJSXCompiler.scala:45: method lines in trait ProcessBuilder is deprecated: Use lineStream instead.
[warn]   private[this] def nativeCompilerDescription = Seq(jsxCommand, "--version").lines.mkString
[warn]                                                                              ^
[warn] /Users/k-sera/Documents/github/skinny-framework/assets/src/main/scala/skinny/assets/ReactJSXCompiler.scala:50: method lines in trait ProcessBuilder is deprecated: Use lineStream instead.
[warn]     try !Seq(jsxCommand, "--version").lines.mkString.isEmpty
[warn]                                       ^
[warn] /Users/k-sera/Documents/github/skinny-framework/assets/src/main/scala/skinny/assets/SassCompiler.scala:27: method lines in trait ProcessBuilder is deprecated: Use lineStream instead.
[warn]       Seq(sassCommand, "-v").lines // > /dev/null
[warn]                              ^
[info] Main Scala API documentation successful.
[info] Packaging /Users/k-sera/Documents/github/skinny-framework/assets/target/scala-2.11/skinny-assets_2.11-1.1.3-javadoc.jar ...
[warn] 7 warnings found
[info] Packaging /Users/k-sera/Documents/github/skinny-framework/assets/target/scala-2.11/skinny-assets_2.11-1.1.3.jar ...

[seratch]

lineStream doesn't exist in Scala 2.10.

[seratch]

We should permit these warnings until the day we will drop Scala 2.10 support.