Drop Scala 2.10, add openjdk7

.travis.yml

@@ -1,7 +1,7 @@
 language: scala
 scala:
-   - 2.10.6
-   - 2.11.7
+  - 2.11.8
 jdk:
-   - oraclejdk8
-   - oraclejdk7
+  - openjdk7
+  - oraclejdk7
+  - oraclejdk8

build.sbt

@@ -14,7 +14,7 @@ def commonSettings: Seq[Setting[_]] = Seq(
   testOptions += Tests.Argument(TestFrameworks.ScalaCheck, "-w", "1"),
   javacOptions in compile ++= Seq("-target", "6", "-source", "6", "-Xlint", "-Xlint:-serial"),
   incOptions := incOptions.value.withNameHashing(true),
-  crossScalaVersions := Seq(scala210, scala211),
+  crossScalaVersions := Seq(scala211),
   resolvers += Resolver.sonatypeRepo("public"),
   scalacOptions += "-Ywarn-unused",
   scalacOptions += "-Ywarn-unused-import",

project/Dependencies.scala

@@ -2,7 +2,6 @@ import sbt._
 import Keys._
 
 object Dependencies {
-  lazy val scala210 = "2.10.6"
   lazy val scala211 = "2.11.8"
 
   val ioVersion = "1.0.0-M6"