Add rnaReverseComplement

Signed-off-by: Ricky Elrod <ricky@elrod.me>
Restructure module layout

Signed-off-by: Ricky Elrod <ricky@elrod.me>
Disable 7.4.2 tests for now (old bytestring's Show is weird)

Signed-off-by: Ricky Elrod <ricky@elrod.me>