Remove references to Python in favour of binary

[agardnerIT]

Some pages: For example: https://agardnerit.github.io/tracepusher/reference/span-events/

Still contain references to running tracepusher as a Python file. Instead, all instructions should be using the binary form.

In other words, site wide, replace:

python ~/tracepusher/tracepusher.py \

With:

./tracepusher \

[agardnerIT]

Closed by #76