If you want to update ammonite, you can do this in the following manner:
curl -L -o ~/bin/ammonite https://git.io/vdNv2
Note: The latest ammonite version can be found on http://ammonite.io. Just exchange the https-URL.
Store the ammonite executable to the local bin folder.
Delete the cache of former ammonite sessions:
rm -rf ~/.ammonite/cache
Create a predef.sc file that loads different dependencies during startup of ammonite.
vim ~/.ammonite/predef.sc
interp.load.ivy("com.lihaoyi" %% "ammonite-ops" % ammonite.Constants.version)
interp.load.ivy("org.typelevel" %% "cats-core" % "1.0.1")
interp.load.ivy("org.typelevel" %% "cats-free" % "1.0.1")
interp.load.ivy("io.monix" %% "monix" % "2.3.3")
interp.load.ivy("io.monix" %% "monix-cats" % "2.3.3")