Added PHP 7.3 to test environments.

Removed geospatial extension from bearing calculations until the bug …

…is rectified.

Coding standards.

Updated README.

signing tag

Updated README to new library syntax.

added php7 support.

Cleaned up vincenty formula and centralised distance calculations int…

…o the Location class.

units are no longer case sensitive.

Merge branch '2.0'

# Conflicts:
#	composer.json