Delete unused OTP deps Makefile and related Dockerfile for compilation
Expose creation of test.img in top Makefile
Test creation of test.img on CI
Express that `bc` needs `test` BEAMs in order to consider rare iops

See `bc/scripts/beam.src`, line `../test/ebin`.
Merge pull request #27 from lucafavatella/purge-unused-deps

Delete unused deps folder
Merge pull request #28 from lucafavatella/test-img

Expose and test creation of test.img
Merge pull request #29 from lucafavatella/bc-needs-test-beams

Express that `bc` needs `test` BEAMs in order to consider rare iops