Update rebar to rebar 2.1.0-pre. This (among other things) fixes a crash if an environment variable contains non-ascii characters
Forgot the changelog
Ensure unquote_splicing followed by tail works, closes #1393
Merge pull request #1392 from pragdave/update-rebar

Update rebar to rebar 2.1.0-pre. This (among other things) fixes a crash...
Remove hopefully uneeded rebar hacks
Install rebar from elixir repo which is more up to date
Improve types for Stream
Pretty printer now prints grouped elements in the same line, closes #1383

This implementation slightly changes the semantic of Lindig's algorithm
to allow elements that belong to the same group to be printed together
in the same line, even if they do not fit the line fully. This was achieved
by changing `:break` to mean a possible break and `:flat` to force a flat
structure. Then deciding if a break works as a newline is just a matter
of checking if we have enough space until the next break that is not
inside a group (which is still flat).