Switched to getting the accountNumber from the ProviderContext.

There is already a built-in accountNumber in ProviderContext, so there
is no need to specify it as a ContextRequirement.
Merge pull request #84 from daniellemayne/develop

bugzid 5066: remove quotes to change from literal text to method call
Merge pull request #87 from oldpatricka/feature/get-accountNumber-from-context-develop

Switched to getting the accountNumber from the ProviderContext.