Switch to Semantic versioning & only put MAJOR version in path to hosted snowplow.js

[alexanderdean]

As per: http://semver.org/

Given a version number MAJOR.MINOR.PATCH, increment the:

MAJOR version when you make incompatible API changes,
MINOR version when you add functionality in a backwards-compatible manner, and
PATCH version when you make backwards-compatible bug fixes.
Additional labels for pre-release and build metadata are available as extensions to the MAJOR.MINOR.PATCH format.

Therefore, we should only be putting the MAJOR version in the path to snowplow.js

[alexanderdean]

Done in 0.13.0.