Update Makefile build_ui target to lerna structure

[tiffon]

Blocked on jaegertracing/jaeger-ui#209.

Blocked on verifying the latest UI. The UI is good to go.

Update the build_ui Makefile target to handle the post-Lerna Jaeger UI folder structure.

[coveralls]

Coverage remained the same at 100.0% when pulling d9b14c6 on tiffon:jaeger-ui-lerna into c7891a4 on jaegertracing:master.

[jpkrohling]

The build for ALL_IN_ONE=true seems to have failed due to:

rm -rf jaeger-ui-build && mkdir jaeger-ui-build
cp -r jaeger-ui/packages/jaeger-ui/build jaeger-ui-build/
cp: cannot stat ‘jaeger-ui/packages/jaeger-ui/build’: No such file or directory
make: *** [build_ui] Error 1

[tiffon]

@jpkrohling Thanks, will update the commit associated with the jaeger-ui repo.

[codecov]

Codecov Report

Merging #798 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           master   #798   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files         126    126           
  Lines        6080   6080           
=====================================
  Hits         6080   6080

---

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 7919cd9...48c0ac1. Read the comment docs.

[yurishkuro]

lgtm, but since this is also pulling the latest UI, can you include the (future) changes in the CHANGELOG in this repo?

[tiffon]

Will do. Also, we are in the process of verifying there wasn't a regression in the latest UI. I'll removed the [Blocked] once that is sorted out.

…