Add an Objektiv cask (easy browser switching)

tl;dr Objektiv is a menubar app to switch default browsers.

Full description taken from the [website][]:

>Objektiv is a utility that lets you switch your default browser
>easily.  You might find it useful if you're a web designer or use
>multiple browsers in your workflow.

[website]: http://nthloop.github.io/Objektiv/
Merge pull request #752 from ciarand/objektiv

Add an Objektiv cask (easy browser switching)
Update xScope to 3.6.1
Merge pull request #753 from NanoXD/xscope

Update xScope to 3.6.1
Add RoyalTSX cask
Merge pull request #754 from NanoXD/RoyalTSX

Add RoyalTSX cask
Add 4K Video Downloader cask
Merge pull request #755 from NanoXD/4kVideoDownloader

Add 4K Video Downloader cask
Update Instacast to 1.0.2
Merge pull request #756 from NanoXD/instacast

Update Instacast to 1.0.2
adding cask for snippets.me
Merge pull request #757 from ShaneDelmore/snippets

adding cask for snippets.me
Updating Espresso to 2.1
Update version to 'latest'
Merge pull request #760 from peteschaffner/espresso-update

Update Espresso to latest
add nocturne 2.0.0

a screen inversion tool - switch your colors to night mode.

also allows temporarily removing window shadows.
Merge pull request #761 from phinze/nocturne

add nocturne 2.0.0
Adding support for local casks outside of the casks directory
Add TravisCI irc integration
Merge pull request #763 from NanoXD/master

Add TravisCI irc integration