Add isometry benchmarks to travis ci benchmark job (#2914)
Add isometry benchmarks to travis ci benchmark job (#2914)

This commit adds the isometry benchmarks to the set of benchmarks we run
in CI. This shouldn't significant additional time to the job run, but
will add a useful benchmarks for tracking the performance of a patch.
Most interestingly it will add a benchmark that doesn't measure time but
instead compares the CNOT count output from the transpiler. Which makes
a lot of sense in this CI job because it won't be bound to the
variable performance of the cloud guests that travis runs it's jobs on.
QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py,QISKit/qiskit-sdk-py