[WIP] Add spellchecker

[emanic]

• Uses Travis CI and hunspell for spellchecker that runs on each PR
• This PR is a work in progress, we still need to fill out our-dict and expand the spellchecking to cover more of the repo content
• We also need to hook Travis CI up to the twistlock/docs repo and configure github to block merges if CI fails
• Works in my fork
• Do not merge yet

[sgordon46]

@iansk changes moved to another PR, this can be closed.

[iansk]

Got it, thanks @sgordon46