Disable parallel execution of tests in spray.

This is a workaround for non-deterministic failures we've observed. See
https://github.com/scala/community-builds/pull/69#issuecomment-63324597
for details.
Merge pull request #74 from gkossakowski/spray-disable-parrallel-tests

Disable parallel execution of tests in spray.
Adding Scala Records to the build.
Merge pull request #72 from vjovanov/scala-records

Adding Scala Records to the build.
Switch to fixed revision of Akka

This is a workaround for #75 until we figure out how to fix it.
Merge pull request #76 from gkossakowski/akka-revert

Switch to fixed revision of Akka
Revert akka to 7a6dab2319b525e479f6bae735d1d1b2f9efb9ff

It seems like my original guess in #75 was wrong. Some other change in
akka build must have broken community build. Let's revert to the last
akka revision that is known to work before we figure out what happened.
Merge pull request #77 from gkossakowski/akka-revert

Revert akka to 7a6dab2319b525e479f6bae735d1d1b2f9efb9ff
Revert akka-libs-210 to 49d90828517bd03dbb52e878430c4af47df33992

This is in the same spirit as #77. We fix the following failure:

[akka-libs-210:error] /localhome/jenkinsdbuild2/workspace/Community-2.11.x/target-0.9.1/extraction/94fbde165839e00534c4e811d5679de9131de75d/projects/802460bf35a671575eeb16ae328523c194910d7e/build.sbt:1: error: not found: value enablePlugins
[akka-libs-210:error] enablePlugins(akka.RootSettings)
[akka-libs-210:error] ^
[akka-libs-210] [error] Type error in expression
[akka-libs-210] Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore?

https://jenkins-dbuild.typesafe.com:8499/job/Community-2.11.x/366/consoleFull

I believe this error is caused by the fact that enablePlugins is available
in sbt 0.13.6 only.
Merge pull request #79 from gkossakowski/akka-revert

Revert akka-libs-210 to 49d90828517bd03dbb52e878430c4af47df33992
Upgrade to sbt 0.13.7.

Macro paradise is kept at 0.13.5 because otherwise it blows up with

[paradise-210] java.lang.NullPointerException
[paradise-210] 	at xsbt.Dependency$ExtractDependenciesByMemberRefTraverser$$anonfun$1.isDefinedAt(Dependency.scala:142)
[paradise-210] 	at xsbt.Dependency$ExtractDependenciesByMemberRefTraverser$$anonfun$1.isDefinedAt(Dependency.scala:141)
[paradise-210] 	at xsbt.Dependency$CollectTypeTraverser.traverse(Dependency.scala:89)

Fixes #80.
Revert "Revert akka-libs-210 to 49d90828517bd03dbb52e878430c4af47df33992"

This reverts commit c8e7d1641fb39a778d1beeb5e66b7500e542f190. We upgraded
to sbt 0.13.7 in previous commit so the workaround from
c8e7d1641fb39a778d1beeb5e66b7500e542f190 is not needed anymore.
Merge pull request #81 from gkossakowski/sbt-upgrade-to-0.13.7

Upgrade sbt to 0.13.7