Move PySkycoin to ./lib/swig

[olemis]

Is your feature request related to a problem? Please describe.
PySkycoin code is scattered immediately under repository root folder .

Describe the solution you'd like

• Move PySkycoin code to ./lib/swig

Describe alternatives you've considered
Other names could work as well , as long as folder be a direct children of ./lib

Additional context

• Makefile and other global scripts / code should remain at their current loctions . Make sure that all references are updated accordingly .
• If possible all Python packages should be generated in a single ./dist folder .