Add dynamic Provider layout generation

[alexandrius]

Solves #11 and possibly #9

[yamalight]

A few small requests - could you please:

• add a test case for multiple stores
• make sure eslint passes (I should probably set it up in npm scripts)
• add note to readme that explains separate contexts for separate stores

[alexandrius]

@yamalight Sorry I'm not eslint expert could you help me with this error:

Oops! Something went wrong! :(

ESLint: 6.1.0.

ESLint couldn't find the config "standard" to extend from. Please check that the name of the config is correct.

The config "standard" was referenced from the config file in "/Users/alex/Documents/Development/ReactNative/outstated/.eslintrc".

If you still have problems, please stop by https://gitter.im/eslint/eslint to chat with the team.

[yamalight]

Ah, right, I forgot there was whole eslint 6.x upgrade issue here as well. OK, disregard eslint, I can do that myself after merge :)

[yamalight]

Looks good, thanks! Will do a release later today