Stacked @card v1.2 : Test cases for Multiple @cards

[valayDave]

Stacked on #897

Test Suite Changes

The MetadataCheck and the CliCheck objects contain assert_card and get_card functions. This PR leverages the card list command introduced in #895 . card list cli command is used by list_cards function in theCliCheck. A similar function is added to MetadataCheck. Both these functions return dicts with the same structure.

The assert_card function now also takes card_id and card_hash as arguments. This makes filtering a single card easily possible.

Test Cases

The test cases are derived from the changes we introduce in #894 . #894 introduces using components from userland i.e. current.card. The below test cases also test and validate the functioning of this user interface.

1. current.card.append/current.card.extend Should work for:

   @card(type='x',id='a')
   @card(type='x')

   @card(type='x')

   @card(type='x',id='a')

   @card(type='x',id='a')
   @card(type='x')
   @card(type='x',customize=True)

2. current.card should not fail :

   1. current.card.append shouldn't fail under ambiguity of resolution
   2. current.card['myid'] shouldn't fail if myid doesn't exist
   3. current.card.get(type='nonexistingtype') shouldn't fail.
   4. current.card.append(SomeRandomType()) shouldn't fail.

3. current.card['myid'] should work for:

   @card(type='x',id='a')
   @card(type='x')
   @step
   def mystep(self):
   	current.card['a'].append

   @card(type='x',id='b') # b is non-editable
   @step
   def mystep(self):
   	current.card['b'].append

4. current.card should not fail on serialization when passing to subprocess. We should have graceful serialization failures which don't intrude in user space.

5. Tests for view/get input argument variations.

6. multiple cards should work@card.