README constain 'Dependencies' that are explicit and implicit
README constain 'Dependencies' that are explicit and implicit

Some dependencies need to be explicitly installed by users while
others are implicitly pulled in during installation of
explicitly intalled dependencies.

Split this into 'Explicit' and 'Implicit' sections in 'Dependencies'

somaticio/tensorflow.rb,somaticio/tensorflow.rb,chrhansen/tensorflow.rb,somaticio/tensorflow.rb,somaticio/tensorflow.rb,somaticio/tensorflow.rb,chrhansen/tensorflow.rb,chrhansen/tensorflow.rb,chrhansen/tensorflow.rb