Fix whitespace
Revert "Restored the CMD instruction to the Dockerfile and removed the CMD instruction explanation, this is a bit of a simplification but is a simplier explanation for a newbie"

This reverts commit 9e53ea71fa9e6f0a71a72530df8bb7c5f17515c2.
Merge branch 'master' into Issue24

Merged whitespace removal commit from upstream master, didn't think i
should rebase branch commits as already pushed commits to my forked
branch so they are public, i am new to pull requests