Allow ENV specific values to have a default

[justin808]

If the NODE_ENV specific value for a setting is not found, then a
non-env specific value is used.

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This change is 

[justin808]

Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on @alexfedoseev)

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src/utils/getEnvProp.js, line 9 at r1 (raw file):

 */
export default function(prop, config) {
  if (prop in config) {

@alexfedoseev I moved this to be used after the node specific value is not found. This is the only change worth reviewing.

[justin808]

@alexfedoseev please do a post-review if I already merged.

Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on @alexfedoseev)