add CodecXz.jl to tests

Author: bicycle1885

README.md

@@ -22,4 +22,3 @@ Consult the [docs][docs-latest-url] for more details and examples.
 [codecov-url]: http://codecov.io/github/bicycle1885/TranscodingStreams.jl?branch=master
 [docs-latest-img]: https://img.shields.io/badge/docs-latest-blue.svg
 [docs-latest-url]: https://bicycle1885.github.io/TranscodingStreams.jl/latest/
-

test/runtests.jl

@@ -89,10 +89,10 @@ using Base.Test
 end
 
 installed = keys(Pkg.installed())
-for pkg in ["CodecZlib", "CodecZstd", "CodecBzip2"]
+for pkg in ["CodecZlib", "CodecBzip2", "CodecXz", "CodecZstd"]
     if pkg ∈ installed
         Pkg.test(pkg)
     else
-        info("Skip ", pkg)
+        info("Skip testing", pkg, ".jl because it is not installed.")
     end
 end