* Allow to create graph space without options

* Addressed @steppenwolfyuetong's comments

* Addressed comments

* Move raftex and wal into kvstore

* Rebase on master

* Append more test case

* append test case

* append more test case

* fix email to EMAIL

* Describe Tag and Edge from metad

* Address dutor's comment

* Fix to

* Integrate raft into storage

All UTs pass. At the moment, all parts still running with single copy. Will enable multiple copies in the future PR

Implemented #178

* Addressed @dangleptr's comments and rebased

* Addressed @dangleptr's comments and rebased

* Addressed @laura-ding's @dangleptr's comments

Rebased as well

* support time to live

* address dangleptr's comments

* address dangleptr's comment

* Clean up dependency on proxygen libs

* Address comments

Unified UTS'graphServer metaServer storageServer, Delete checkSpaceExist(), Delete FileBasedSchemaManager, Move AdHocSchemaManager to storage/test (#412)

* Delete checkSpaceExist(), Delete FileBasedSchemaManager, Move AdHocSchemaManager to storage/test

* Unified UTS'graphServer metaServer storageServer
Make goTest work

* rebase master and add annotation

* Add log

* Addressed boshengchen and dangleptr's comments

* fix build error

* Fix UT failed

* support desc keyword

* support desc keyword

* fix dutor comment

* fix test case

* Use active hosts when creating space

* x

* support describe space

* support describe space

* support desc space

* address dangleptr's comment

* address dutor's comment

* using async

* address dangleptr's comment

* fix

* fix copyright

* address dangleptr's comment

* fix

* fix

* modify remove to drop in admin commands

* recovery remove hosts

* address laura-ding's comment

* Use ephemeral port to bind on in tests

* let the system choose an available port

* rebase master

* address dutor's comments

* Adjust meta client ctor  && implement heartbeat logic inside.

* Address laura-ding's comments

* Fix conflicts

* To add a web interface to indicate the status of the three daemons

* address dutor's comments

* address sherman-the-tank's comments

* address dutor's comments

* rebase master

* Support unreserved keywords

* Reserve keyword TAG, VERTEX and EDGE

* alter edge

* address comments

* address comments and fix error using typeId function

* Reorganized all linters into the same directory

* Fix

* support semicolon in console command

* using while to determine the loop ending

* All files committed in docs

* Update README.md

*  update nQGL

* fix typos in FindGPERF.cmake

*  fix typo in FindReadline.cmake

* fix table

*  fix table

* update readme 5.14.2019

* readme add slack link

* Remove space keyword in UseSpaceSentence && update get-started.md

* Update nGQL.md

* support show tags and edges

* support remove tag and edge

* address dangleptr's comments

* support edge in meta service

* support leader

* fix toString function defect

* address dangleptr's comments

* address dutor's comments