Aliases with hyphens break shell

Created by: theduke

Reproduction: Defining an alias with a hyphen is currently not possible.

Example:

alias test-me='echo lala'
test-me 
// ion: command not found: test-me

It get's even worse when the alias is more complex. This completely breaks a regular command:

alias git-start='git init && git commit -m "Initital commit" --allow-empty'
git-start
// ion: command git-start not found
git init
// command not found: tart=git (!!)

Expected behavior

Aliases with hyphens work.

Actual behavior:

Aliases with hyphens don't work and even break regular commands.

Build information:

• rustc 1.26.0-nightly (e026b59cf 2018-03-03)
• ion 1.0.0-alpha (x86_64-unknown-linux-gnu) rev 96d5b5d2
• Linux hp.devices.theduke.at 4.15.5-1-ARCH