Merge pull request #5 from Philippus/scala-2.11.x

Cross-build for Scala 2.11.x and 2.12.x

.travis.yml

@@ -1,5 +1,6 @@
 language: scala
 scala:
+   - 2.11.12
    - 2.12.4
 jdk:
    - oraclejdk8

README.md

@@ -15,7 +15,8 @@ To view the emoji itself you will need an emoji library such as [Lightbend Emoji
 
 ## Installation
 
-Add the following to your `build.sbt`:
+Emoji-clock is published for Scala 2.11 and 2.12, but requires Java 8. To start using it add the following to your
+`build.sbt`:
 
 ```
 resolvers += Resolver.bintrayRepo("gn0s1s", "releases")

build.sbt

@@ -5,7 +5,8 @@ startYear := Some(2017)
 homepage := Some(url("https://github.com/philippus/emoji-clock"))
 licenses += ("MIT", url("http://opensource.org/licenses/MIT"))
 
-scalaVersion := "2.12.4"
+crossScalaVersions := List("2.11.12", "2.12.4")
+scalaVersion := crossScalaVersions.value.last
 
 bintrayOrganization := Some("gn0s1s")
 bintrayRepository := "releases"