eliminate the redundant empty line in the extracted individual test case

[dreig]

Addresses #79

The redundant empty line can be traced to "ast.go", where the Elts attribute of the AST-node representing the slice of all test cases is replaced with the Elts attribute of an AST-node representing an individual test case. It can be observed in the following diff of the (partial) AST:

I opted for replacing all of the contents of the slice-node (not just Elts, but also Lbrace)

[coveralls]

Pull Request Test Coverage Report for Build 3321542438

• 4 of 4 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 77.843%

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Totals
Change from base Build 3321320140:	0.0%
Covered Lines:	397
Relevant Lines:	510

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💛 - Coveralls

[junedev]

@ErikSchierboom Your comment says you approved but GitHub does not show any approval.

[junedev]

I reviewed this and it looks all fine and works as expected. Well done @dreig.

I would prefer if we could improve the tests as stated in the comment but if that turns out to be difficult, this can be merged as is.