Standardizing spec tests

Since the `to_s` has been fixed for Razor::Command, the standard for spec tests should be `describe Razor::Command::$command_name do...`. This removes a redundancy too in `it_behaves_like "a command"`.

Fixes https://tickets.puppetlabs.com/browse/RAZOR-240
Handle cases where command's attribute has no datatype

Fixes https://tickets.puppetlabs.com/browse/RAZOR-268
Wrong error for multiple create-broker commands

Running `create-broker` multiple times with the
same arguments was causing the broker types to
be compared incorrectly. This corrects that behavior.

Fixes https://tickets.puppetlabs.com/browse/RAZOR-251
Release 0.15.0
Docs: Fixing up documentation spacing

There were some minor issues where extra spaces would be added, indentations
wouldn't quite match up, etc. This tidies and standardizes those in the
general case.

Fixes https://tickets.puppetlabs.com/browse/RAZOR-213
Docs: Improving punctuation and spacing

Punctuation and other minor fixes for individual command help messages.

Fixes https://tickets.puppetlabs.com/browse/RAZOR-270
Fixing api.md for `create-policy`

Removing example that creates a tag inside `create-policy`.