Always return the last Cal entry (don't worry about how old it might be)

[jasoncalabrese]

Also some refactoring by using async.parallel to make multiple ongo requests at once.

Bonus fix: also check env.DISPLAY_UNITS if the units query string param isn't set

@bewest @ELUTE @jimsiff

[coveralls]

Coverage decreased (-1.18%) to 71.34% when pulling d08f5f7 on wip/last-cal into 1e27704 on dev.

[coveralls]

Coverage increased (+0.25%) to 72.77% when pulling 2dc7536 on wip/last-cal into 1e27704 on dev.

[coveralls]

Coverage increased (+0.37%) to 72.89% when pulling 6357212 on wip/last-cal into 1e27704 on dev.

[coveralls]

Coverage increased (+0.2%) to 72.73% when pulling 7b6f054 on wip/last-cal into 1e27704 on dev.

[coveralls]

Coverage increased (+0.2%) to 72.73% when pulling 7b6f054 on wip/last-cal into 1e27704 on dev.

[coveralls]

Coverage increased (+0.21%) to 72.69% when pulling 896ae9e on wip/last-cal into ebcb49c on dev.

[coveralls]

Coverage increased (+0.21%) to 72.69% when pulling 3162422 on wip/last-cal into ebcb49c on dev.

[jasoncalabrese]

@jimsiff, @ELUTE, I talked to @YYGIRL about some users are burning through data partially due to the extra cal data returned from /pebble. We merged in a fix (6357212) that selectively chooses the fields that are needed. The plan is to have some of those users that are most concerned about data usage to start using dev after this PR is merged. Then they can also help test before we release Enchilada to master.

[jimsiff]

JSON payload is reduced about 40% but TCP and HTTP protocol overhead drops the net savings to 20%. Gzip encoding may help some more.

[jasoncalabrese]

thanks for testing @jimsiff did you also take a look at the main web monitor page, in addition to /pebble?

[coveralls]

Coverage increased (+0.21%) to 72.69% when pulling b7fc6b9 on wip/last-cal into ebcb49c on dev.

[jasoncalabrese]

I just added gzip compression to everything, with that we're down to 255 bytes (455 with http overhead)

[coveralls]

Coverage increased (+0.21%) to 72.69% when pulling 206a8fd on wip/last-cal into ebcb49c on dev.

[coveralls]

Coverage increased (+0.21%) to 72.69% when pulling bcd3fa0 on wip/last-cal into ebcb49c on dev.

[coveralls]

Coverage increased (+0.21%) to 72.69% when pulling a1f963a on wip/last-cal into ebcb49c on dev.