Update elixir version to 1.0.0
Merge pull request #16 from niku/update-elixir

Update elixir version to 1.0.0. Thanks to @niku
fix `cache_path: command not found` error

- the following error occurred when `always_rebuild` is true
       Cleaning all cache to force rebuilds
/tmp/buildpack_xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx/lib/misc_funcs.sh:
line 92: cache_path: command not found
Merge pull request #17 from ma2gedev/cache_path_error

fix `cache_path: command not found` error
Use unzip on Cedar-14 stack, else fallback to jar
Merge pull request #19 from HashNuke/cedar-14-unzip-fix

Fix #18: Use unzip on Cedar-14 stack, else fallback to jar
Mix handles if elixir version changed
Test