Refactors the source to be portable, compiles with portable compiler
(supports clang and gcc now) and includes a lot of dockerized testing
to assure that it works on different JVMs and libcs.

One interesting part of this is that while compilation requires a JDK,
the generated .so does not link to any JVM libraries. As long as the
JVMTI interface remains stable (tested to be true on at least Java 8 and
Java 11) jvmquake should continue functioning.

When new Java's arrive we can just add them to our test matrix!

This software is used in production at Netflix, we should indicate it is
past Beta.

This integrates with our travis and OSSMETADATA as well

Introduces key->value kwargs for parsing out two new optional options, a
warning threshold and a path on the filesystem to touch when we get a
warning. This way you can monitor that file's modification time and
automatically begin capturing CPU profiles or other diagnostic
information when we are approaching OOM behavior (or just general bad GC
behavior).

We now handle all possible errors by causing a SIGABRT and subsequent
kill. These errors could only happen if something is misconfigured so we
consider them bugs and choose to die quickly.

Also updated the tests and docs

This hopefully makes it easier for folks to get started

This moves everything to docker, and ports the last test to python (so
now all 6 test cases are running via python)

This way we can actually assert things about the world that we expect
like certain files should be created or not and such.

This lays out the basic framework for the jvm-watchdog jvmti agent which
will attach to any JVM that is compliant with the JVMTI spec and ensure
that the JVM dies when unstable.