Merge pull request #13 from olleolleolle/master

Improved README and reduced dependencies and linted
Store statistics for sent messages, close #5
Merge remote-tracking branch 'origin/master'

Conflicts:
	core.py
	core_test.py
Don't split groups by phone

The functionality to attach different groups to different receiving
phones is not used and could be solved by running different smskrupp
instances.

By removing it we will be able to receive messages on different
sim-cards while still sending to groups using one output phone.
Add dump-groups command
Add group sendout command and unicode cli fixes
remove group-sendout, can be done by fake-incoming
Whitespace
Add change-number command

Fixes #12