Cucumber Tests to validate min-balance field from algod v2/Accounts/{{Account}} response

[jds1g14]

As per the issue issue 286, the testing sdk has been updated to include a test which validates the min-balance field received from algodv2 accounts call.

The test has been given an unusual tag of @accounts.min-balance so as to avoid the test case running (and failing) as part of any integration/unit test for an SDK in which this change has not been made for.

[CLAassistant]

All committers have signed the CLA.

[jds1g14]

Hey @tzaffi could you re-review when you have a minute, thanks.

[gmalouf]

We have added min-balance to the indexer API spec and have regenerated the individual SDK specifications where warranted.