Merge pull request #331 from alexarchambault/topic/okhttp

Add okhttp plugin

build.sbt

@@ -570,8 +570,18 @@ lazy val `http-server` = project
     )
   )
 
+lazy val okhttp = project
+  .dependsOn(cache)
+  .settings(commonSettings)
+  .settings(
+    name := "coursier-okhttp",
+    libraryDependencies ++= Seq(
+      "com.squareup.okhttp" % "okhttp-urlconnection" % "2.7.5"
+    )
+  )
+
 lazy val `coursier` = project.in(file("."))
-  .aggregate(coreJvm, coreJs, `fetch-js`, testsJvm, testsJs, cache, bootstrap, cli, plugin, web, doc, `http-server`)
+  .aggregate(coreJvm, coreJs, `fetch-js`, testsJvm, testsJs, cache, bootstrap, cli, plugin, web, doc, `http-server`, okhttp)
   .settings(commonSettings)
   .settings(noPublishSettings)
   .settings(releaseSettings)

okhttp/src/main/scala/coursier/cache/protocol/HttpHandler.scala

@@ -0,0 +1,17 @@
+package coursier.cache.protocol
+
+import java.net.{URLStreamHandler, URLStreamHandlerFactory}
+
+import com.squareup.okhttp.{OkHttpClient, OkUrlFactory}
+
+object HttpHandler {
+  lazy val okHttpClient = new OkHttpClient
+  lazy val okHttpFactory = new OkUrlFactory(okHttpClient)
+}
+
+class HttpHandler extends URLStreamHandlerFactory {
+  def createURLStreamHandler(protocol: String): URLStreamHandler =
+    HttpHandler.okHttpFactory.createURLStreamHandler(protocol)
+}
+
+class HttpsHandler extends HttpHandler