fix(iec_meter): entity validator implemantation to prevent duplication iec_meter (contract_id+meter_serial)
feat: get and save iec electricity raw data.
fix(electricity_raw): change param cumulative_kwh => kWh.
Merge pull request #43 from Gizra/42

fix(electricity_raw): change param cumulative_kwh => kWh.
feat(electricity): validate that a reading of a meter in a specific time, will be record only one time.
Merge branch 'master' of github.com:Gizra/negawatt-server
Add normalizer plugins.
Add Travis.
Add Travis build icon.
Fix make file.
Merge pull request #52 from Gizra/fix-make

Fix make file.

entity-validator and RESTful were not download properly.
Add IEC normalizer plugin.
Accept meter node and process all frequencies and rate types.

Also, add a Drush process-meter command.
feat(restful): prepare resources "/api/accouts", "/api/iec_meters", "/api/electricity" to works with the client application.
Meter category migrate
Add RESTful resource for Meter category.
Merge pull request #63 from Gizra/tags-tree

Add RESTful resource for Meter category.
Use a temporary branch for RESTful.
reorder result like a tree according relation parent/child.
Consolidate the client app with the repo.