feat(GraphQLTemplate) option to externalize fetching, Related #70

[jleibund]

Allows substitution for Fetch when necessary.

[CLAassistant]

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6 out of 7 committers have signed the CLA.

:white_check_mark: bpillai
:white_check_mark: mkalen
:white_check_mark: chemdrew
:white_check_mark: mrchass
:white_check_mark: jleibund
:white_check_mark: magp3
:x: Jake Tusa

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[coveralls]

Pull Request Test Coverage Report for Build 92

• 4 of 4 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.004%) to 99.057%

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Totals
Change from base Build 91:	0.004%
Covered Lines:	525
Relevant Lines:	530

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💛 - Coveralls

[jleibund]

will try that again..