[BUG][URGENT] FISTA and POGM converge in single iteration!

[chaithyagr]

System setup
OS: [e.g] macOS v10.14.1
Python version: [e.g.] v3.6.7
Python environment (if any): [e.g.] conda v4.5.11

Describe the bug
Currently, FISTA and POGM algorithms seem to converge in a single iteration.
The reason being that we have added a comma for python style guide:

ModOpt/modopt/opt/algorithms.py

Lines 1548 to 1552 in 616c9e7

	if self._cost_func:
	self.converge = (
	self.any_convergence_flag()
	or self._cost_func.get_cost(self._x_new),
	)

ModOpt/modopt/opt/algorithms.py

Lines 789 to 793 in 616c9e7

	if self._cost_func:
	self.converge = (
	self.any_convergence_flag()
	or self._cost_func.get_cost(self._x_new),
	)

These make self.converge into a tuple, i.e. (False,)!
Due to this, the check for convergence later here :

ModOpt/modopt/opt/algorithms.py

Lines 317 to 320 in 616c9e7

	if self.converge:
	if self.verbose:
	print(' - Converged!')
	break

Becomes true and the code ends.

We need to remove the commas from the above lines.
Also @sfarrens can we keep this issue to add tests for this? It seems like a very important bug that we should have not missed.

Are you planning to submit a Pull Request?

• Yes
• No

[chaithyagr]

I think we can close this. This was addressed in #114