Documentation indicates ML components need to be installed on YARN nodemanagers - this is wrong

The Spot documentation makes mention of needing the ML components installed on YARN node managers in several sections:

• Diagram in "Pure Hadoop" section
• Paragraph below diagram
• Table in section 2

This should be corrected to reflect that the ML components only need to be installed on the gateway/edge node since the appropriate libraries will be shipped as part of the YARN job to the node managers.