Add coverage analysis to Travis test and upload to coveralls

Also, replace git-stamp plugin with newer version since one of its
dependency is binary-incompatible with sbt-coveralls.

.travis.yml

+language: scala
+
+scala:
+    - 2.11.6
+
+jdk:
+    - oraclejdk8
+
+cache:
+  directories:
+    - $HOME/.m2/repository
+    - $HOME/.sbt
+    - $HOME/.ivy2
+
+script:
+    - sbt ++$TRAVIS_SCALA_VERSION clean coverage test it:test
+
+after_success:
+    - sbt coveralls

project/SentinelBuild.scala

 import sbt._
 import Keys._
 import org.scalatra.sbt._
-import com.atlassian.labs.gitstamp.GitStampPlugin._
 import com.earldouglas.xwp.XwpPlugin._
 import com.typesafe.sbt.SbtScalariform._
 import com.typesafe.sbt.SbtSite.site
 import de.heikoseeberger.sbtheader._
 import sbtassembly.{ AssemblyKeys, MergeStrategy, PathList }, AssemblyKeys._
+import uk.gov.hmrc.gitstamp.GitStampPlugin._
 
 object SentinelBuild extends Build {
 

project/plugins.sbt

-addSbtPlugin("com.atlassian.labs" % "sbt-git-stamp" % "0.1.2")
-
 addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.13.0")
 
 addSbtPlugin("com.mojolly.scalate" % "xsbt-scalate-generator" % "0.5.0")
@@ -12,4 +10,8 @@ addSbtPlugin("de.heikoseeberger" % "sbt-header" % "1.5.0")
 
 addSbtPlugin("org.scalatra.sbt" % "scalatra-sbt" % "0.4.0")
 
+addSbtPlugin("org.scoverage" % "sbt-coveralls" % "1.0.0")
+
 addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.1.0")
+
+addSbtPlugin("uk.gov.hmrc" % "sbt-git-stamp" % "5.1.0")