Add a flag for getting post meta as a single value or not

[BhargavBhandari90]

Fixes #325

• Currently marked as WIP.
• I haven't wrote behat tests for this yet.
• Let's finalize the changes first and then I'll write the tests.

What I did

• Added a flag --is-single
• Default value will be 1 ( true ) which was already there.
• And we can now pass 0 as false for getting multiple values

Command Examples

• wp post meta get 1 bwp_key --is-single=0
• wp post meta get 1 bwp_key --is-single=1

[BhargavBhandari90]

@swissspidy After your feedback, now command will be

• wp post meta get 1 bwp_key --single // For true
• wp post meta get 1 bwp_key --no-single // For false

And without the single flag it will work the way it was working.

[swissspidy]

Sounds good! Next steps: tests.

[BhargavBhandari90]

@swissspidy Yep. On it