Reconfigure Docker for Pre-Release and Autobuild

[dbkbali]

• removed redundant dockerfiles
• Moved geth dockerfile to root directory to facilitate autobuild
• Updated docker-compose files to point to root dockerfile

Our dockerhub autobuild tasks were erring as dockerhub can only autobuild from Docker files located in the root directory, this fixes that issue and also minimizes the geth image for development as well.

All tests are green and also manually tested that docker images can be built.

Once I have approval to merge this I will proceed to create a formal release and merge request to merge development into staging.

[dbkbali]

@dutterbutter strange failure here - same set of tests passing on push hook - failing on pr hook? any ideas as to why we are seeing this behaviour from Travis?

[GregTheGreek]

@dbkbali What does the handshake test do? Seems to be rooted from there WARN [11-20|02:44:20.471] b99076c0: handshake failed with remote peer 7d18b2ca: Handshake error: Message handler error: (msg code 0): network id mismatch 2 (!= 1)

[dbkbali]

@GregTheGreek the handshake test involves testing networking between peers. We are getting inconsistent results for the travis build involving AMD-Darwin (Mac OSx) - as you will note the builds for that failing test were run twice - once for the push (which passed) and once for the pr (which failed). As both code is identical this shouldnt occur. After consulting with @dutterbutter and looking at the tests run by go_ethereum (they dont run an AMD-Darwin Build), it appears that Travis may have issues with builds which involve AMD-Darwin/Macosx networking. Given these inconsistencies I have removed the AMD-Darwin build from travis. In addition for one of the builds we have turned on submodules true so that we are at least running contract tests on one of our builds.