Add private community test for CI

[echevrier]

Fix #59

• Clean demo-private-community.sh file.
• Add sleep after migration, because of CI failed. See #Complete meetup: claim rewards and test balances #33 (comment)
• Add test: verify Bob's balances in native and community currency

[brenzi]

community currency should actually be reported as a float value by the cli and I'd expect Bob to have 1.0 units as reward for the demo community(not sure about the config). I don't understand why the cli reports the u128 representation. I can live with u128 rep for now, but:

This test is flawed, because bash can't handle bigint. It is a coincidence that this passes. It won't pass if the community income is set to 1000000 units. Our balance type U64F64 fixpoint is to big in its integer representation. tested on my ubuntu machine:

bash> ((X=2**64)); echo $X
0

that means, bash can't handle u128. Another proof:

 if [ 69996761838461427612 -gt 69996761838461427611 ]; then echo "yes"; fi
bash: [: 69996761838461427612: integer expression expected

you should use bc instead:

echo "69996761838461427610<69996761838461427611" | bc
1

[brenzi]

LGTM, thx