Throw not implemented exception when using recalc_price in prod or dev

[phahulin]

• What is it? (leave one option)
  • (Improvement) of existing functionality

Closes #164

[coveralls]

Pull Request Test Coverage Report for Build 513

• 0 of 2 (0.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.3%) to 81.355%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
web-dapp/server-lib/recalc_price.js	0	2	0.0%
<!--	Total:	0	2	0.0%	-->

Totals
Change from base Build 511:	-0.3%
Covered Lines:	997
Relevant Lines:	1192

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💛 - Coveralls