Sets box-sizing to `border-box`
Get the range offset left relative to the viewport

Fixes issue #78
`getBoundingClientRect` gets the position relative to the viewport
Builds distribution files
Merge pull request #83 from andreruffert/range-position-relative-to-viewport

Calculates `.rangeslider` position relative to the viewport
Rename LICENSE-MIT.txt to LICENSE.md :punch:
Update LICENSE.md
Adds a jQuery Plugin Package Manifest
Adds docs url to jQuery Plugin Package Manifest
Version bump to v0.3.3
Merge pull request #85 from andreruffert/release-0.3.3

Release 0.3.3