Problem initializer

[sesevgen]

1. Several improvements to COG
2. Dataset generation pipeline added to COG
3. problem_initializer helper added.
4. Refactored recurrent yaml reading into a Worker method.
5. Added a CheckAndDownload method to Problem.

[tkornuta-ibm]

This pull request introduces 22 alerts and fixes 1 when merging 05f6dd9 into 68ad04d - view on LGTM.com

new alerts:

• 8 for Comparison using is when operands support __eq__
• 8 for Unused import
• 3 for Signature mismatch in overriding method
• 1 for Unused local variable
• 1 for Unreachable code
• 1 for Unnecessary delete statement in function

fixed alerts:

• 1 for 'import *' may pollute namespace

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Comment posted by LGTM.com

[tkornuta-ibm]

This pull request introduces 5 alerts and fixes 3 when merging 7648ac1 into 68ad04d - view on LGTM.com

new alerts:

• 3 for Signature mismatch in overriding method
• 1 for Unused local variable
• 1 for Unnecessary delete statement in function

fixed alerts:

• 2 for Comparison using is when operands support __eq__
• 1 for 'import *' may pollute namespace

---

Comment posted by LGTM.com

[tkornuta-ibm]

This pull request introduces 5 alerts and fixes 3 when merging 7a0e01b into 68ad04d - view on LGTM.com

new alerts:

• 3 for Signature mismatch in overriding method
• 1 for Unused local variable
• 1 for Unnecessary delete statement in function

fixed alerts:

• 2 for Comparison using is when operands support __eq__
• 1 for 'import *' may pollute namespace

---

Comment posted by LGTM.com