bump sbt and have travis update paulp/sbt-extras

.travis.yml

@@ -23,6 +23,8 @@ before_install:
 - mkdir -p ~/.local/bin
 - export PATH=$HOME/.local/bin:$PATH
 - travis_retry curl -L https://www.stackage.org/stack/linux-x86_64 | tar xz --wildcards --strip-components=1 -C ~/.local/bin '*/stack'
+# Download paulp/sbt-extras because Travis CI's copy is 3 years old as of this writing
+- curl -Ls https://git.io/sbt > ~/.local/bin/sbt && chmod 0755 ~/.local/bin/sbt
 
 install:
 - stack ghc -- --version

runtime-jvm/project/build.properties

@@ -1 +1 @@
-sbt.version=0.13.17
+sbt.version=1.1.6