Problem: Dev environment is outdated and no integration with Tendermint

[muawiakh]

Description

• Updated docker-compose.yml
• Remove docker-compose.rdb.yml because RethinkDB is not supported with BigchainDB v2.0
• Update Travis configuration to test with localmongodb and BigchainDB v2.0 instead of BigchainDB <=1.3.0 and rethinkdb.
• Consolidate all deployment methods in a single docker-compose file i.e. docs.yml should move into docker-compose.yml as well.
• Remove dev.yml because it is deprecated(RethinkDB is not supported with 2.0)

Issues This PR Fixes

Fixes #368

:fire::fire::fire: Travis will fail with this PR but we will have dependent changes that will take care of those tests @codegeschrei can confirm :fire::fire::fire:

[codegeschrei]

Sorry for the mess.

[codegeschrei]

I think the basics are working for now. We might encounter more problems later but that's why I also created a branch to collect all changes for bdb-2.0, so we can fix everything step by step before it goes into master.