Add Dockerfile

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I think shipping around a docker container will help make contributing easier:

• by removing the need to manually add support to each distribution: we'd only have to support Debian.
• help people whose computers aren't as powerful by allowing them to avoid compiling the toolchain. They'd only need to download the container.
• avoid cluttering the user's machine by keeping all of the dependencies separate

[mrutt92]

Big fan of anything that makes life easy.

[drichmond]

The Synopsys tools don't work in Debian

[drichmond]

I like this PR, I also like things that make life easy, but our target at the moment is RHEL/Centos distributions.

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Sure, it won’t be too much work to switch to a RHEL-based container. I’ll try to amend this PR tonight.

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"It won't be too much work" - famous last words :)
I was able to get all the regression tests to pass with this Dockerfile, this time it's CentOS-based.