Make `MAX_BIG_NUMBER` consistent across API v3 models

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• I'm submitting a ...

  • bug report
  • feature request
  • support request => Please do not submit support request here, see note at the top of this template.

• Do you want to request a feature or report a bug?
  At present, the MAX_BIG_NUMBER is not consistent across API v3 Django data models. The value should either be 1.0e8 or 1.0e9, or we should have multiple max values.

• What is the current behavior?
  MAX_BIG_NUMBER is not used in some places because its not consistent with maximum possible value in REopt.jl.

• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via
  https://plnkr.co or similar (you can use this template as a starting point: http://plnkr.co/edit/tpl:AvJOMERrnz94ekVua0u5).
  Open models.py in reoptjl app and compare MAX_BIG_NUMBER with the maximum values required in various models.

• What is the expected behavior?
  All maximum values in Django models are either MAX_BIG_NUMBER or are separately declared along with MAX_BIG_NUMBER.

• What is the motivation / use case for changing the behavior?
  To make it easy to align REopt.jl inputs and API v3.

• Please tell us about your environment:

  • REopt API Version: X.X.X
  • Operating System: [all | TypeScript X.X | ES6/7 | ES5 | Dart]
  • Python version: 3.x
  • Julia version: 1.x

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, gitter, etc)

Open models.py in the reoptjl app and compare MAX_BIG_NUMBER with the maximum values required by the various API v3 Django models and by REopt.jl. Determine whether one shared value is sufficient or whether models need separately declared maximums. Done means the model maximums consistently use MAX_BIG_NUMBER or explicitly declare an additional value.