(Feature) Add dockerfile

[fernandomg]

Included Dockerfile contains travis, which may be helpful for running local test in a container before creating the PR.

Steps to use it:

1. install docker https://docs.docker.com/install/#supported-platforms
2. move to the project root
3. docker build -t tw . (where tw is the name of the docker image created and . is the location of the Dockerfile)
4. docker run -ti tw
5. once the image has started, run travis compile > ci.sh
6. edit ci.sh file and set the corresponding branch (search for branch word and replace: branch\=\'\' with branch\=\'master\')
7. bash ci.sh

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Docker build can receive three arguments author, project, branch.
Default values:

• author: poanetwork
• project: token-wizard
• branch: master

So you can build a docker image pointing to a specific author/project/branch.
i.e.: docker build -t tw . --build-arg branch=2.0 will create the image pointing to branch 2.0

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Important: Before running bash ci.sh you have to always find/replace the branch that the ci.sh is pointing to.

[coveralls]

Pull Request Test Coverage Report for Build 2962

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 20.347%

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Totals
Change from base Build 2950:	0.0%
Covered Lines:	834
Relevant Lines:	3594

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💛 - Coveralls