ensure cleaner PATH in test environment
Homebrew homepage location changed
Merge pull request #428 from almog/master

 Homebrew homepage moved to a new location
Clarify the search precedence for .ruby-version files.

Closes #432 [ci skip]
Install a more recent version of Ruby in README instructions
check if completion script is readable

fixes #444
fix rehash when paths have spaces in them

fixes #450
add fish shell support
cleanup in fish

Use process subtitution syntax:

    . (rbenv init -|psub)

instead of:

    eval (rbenv init -)

because the latter doesn't work well with newlines.
fix `rbenv()` function in ksh and dash

ksh syntax becomes:

    function rbenv {
      typeset command

`typeset` only declares a local variable if there's an explicit
`function` declaration; otherwise the variable leaks.

Other shells use this syntax:

    rbenv() {
      local command

This is for dash compatibility, which supports neither `function` nor
`typeset`.

references #205, fixes #408
Merge branch 'shell-fixes'
Merge remote-tracking branch 'upstream/master' into integrate

Conflicts:
	README.md
	libexec/erlenv-init
	libexec/rbenv-sh-rehash
	libexec/rbenv-sh-shell
	test/init.bats
	test/shell.bats
	test/test_helper.bash
modify completions/erlenv.fish to work with erlenv rather than rbenv
fix sh-shell and sh-rehash
fix tests
last bit of cleanup