Provide target info on shell invocation

[adamleff]

When in inspec shell, you need to type the help command to find out info
about your target system. This info would be super helpful right out of the
gate so users have confidence that they're targeting the correct system.

The target info is still available via the help command as it always has
been, as well.

/cc @hannah-radish

[alexpop]

Makes sense. In terms of styling, I removed one line, indented and aligned the values and I feel it looks a bit cleaner. @hannah-radish ?

Diff:

diff --git a/lib/inspec/shell.rb b/lib/inspec/shell.rb
index 226ffb7..ec198fd 100644
--- a/lib/inspec/shell.rb
+++ b/lib/inspec/shell.rb
@@ -100,10 +100,9 @@ module Inspec
       ctx = @runner.backend
       puts <<EOF
 You are currently running on:
-
-    OS platform:  #{mark ctx.os[:name] || 'unknown'}
-    OS family:  #{mark ctx.os[:family] || 'unknown'}
-    OS release: #{mark ctx.os[:release] || 'unknown'}
+  OS platform: #{mark ctx.os[:name] || 'unknown'}
+  OS family:   #{mark ctx.os[:family] || 'unknown'}
+  OS release:  #{mark ctx.os[:release] || 'unknown'}
 EOF
     end

[hannah-radish]

It looks beautiful! Output is really clean. Thank you @adamleff
Let's go with the indentation and extra line (top one)

[arlimus]

Love it + great coding, kudos Adam!!

[chris-rock]

Great idea to show that information out-of-the-box. I agree with Alex, that less spaces in front look better. Nevertheless, I would like to keep the newline.

[arlimus]

rebased