Migrate to now 2

[kt3k]

Now 2 was released in Nov 2, 2018. It's a wrapper of AWS Lambda unlike Now 1. We're still able to use express.js in it by using @now/node-server builder. But I think that's not the way Now 2 recommend. So I separated endpoints into several small micro apps and made them into separate lambda endpoints.

[codecov]

Codecov Report

Merging #31 into master will decrease coverage by 2.23%.
The diff coverage is 84.58%.

@@            Coverage Diff             @@
##           master      #31      +/-   ##
==========================================
- Coverage   92.58%   90.34%   -2.24%     
==========================================
  Files          25       31       +6     
  Lines         364      487     +123     
==========================================
+ Hits          337      440     +103     
- Misses         27       47      +20

Impacted Files	Coverage Δ
util/array.js	100% <ø> (ø)
domain/check-service.js	100% <ø> (ø)
domain/user.js	100% <ø> (ø)
util/date.js	100% <ø> (ø)
domain/daily-check-record.js	83.33% <ø> (ø)
domain/user-init-service.js	100% <ø> (ø)
domain/activity-service.js	83.33% <ø> (ø)
domain/activity.js	100% <ø> (ø)
domain/check-collection.js	100% <ø> (ø)
domain/button.js	100% <ø> (ø)
... and 33 more

---

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[codecov]

Codecov Report

Merging #31 into master will decrease coverage by 2.23%.
The diff coverage is 84.58%.

@@            Coverage Diff             @@
##           master      #31      +/-   ##
==========================================
- Coverage   92.58%   90.34%   -2.24%     
==========================================
  Files          25       31       +6     
  Lines         364      487     +123     
==========================================
+ Hits          337      440     +103     
- Misses         27       47      +20

Impacted Files	Coverage Δ
util/array.js	100% <ø> (ø)
domain/check-service.js	100% <ø> (ø)
domain/user.js	100% <ø> (ø)
util/date.js	100% <ø> (ø)
domain/daily-check-record.js	83.33% <ø> (ø)
domain/user-init-service.js	100% <ø> (ø)
domain/activity.js	100% <ø> (ø)
domain/check-collection.js	100% <ø> (ø)
domain/button.js	100% <ø> (ø)
domain/activity-repository.js	100% <ø> (ø)
... and 33 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update aa33478...380ddd3. Read the comment docs.