Set runtime spec version to 13 and joystream-node binary version to v2.2.0

[mnaamani]

• Preparing final runtime versioning for Constantinople release.
• Adjusting runtime parameters: Unbonding period for validators and modifying the reward curve as per Runtime changes for Rome #388
• Update docker files to allow building joystream/node with Rust v1.43.0

[mnaamani]

@bwhm just wanted to bring your attention to this change of the max_piece_count. I increased it following change to max_inflation and ideal_stake because the unit test failure suggested so:

---- __srml_staking_reward_curve_test_module::reward_curve_precision stdout ----
thread '__srml_staking_reward_curve_test_module::reward_curve_precision' panicked at '
Generated reward curve approximation differ from real one:
	for i = 364050 and base = 1000000, f(i/base) * base = 138165,
	but approximation = 138856,
	err = 0005001 millionth,
	try increase the number of segment: 40 or the test_error: 5000.

[shamil-gadelshin]

LGTM