Updates for pKa challenge

[MehtapIsik]

I updated the repo to match the announcement I will make today regarding pKa challenge. Updates include:

• deadline extension to January 19th, 2018
• clarification that predicted values for type II submissions should be written in scientific number format following Python's syntax: Using e or E to indicate decimal base.
• clarification about the meaning of type II template column titles
• addition of one missing SM10 microstate: SM10_micro037
• correction to Predictions: keyword in commented-out lines of template files.

@davidlmobley Could you please approve this pull-request? I will wait for this merge to send out an announcement email to participants covering these items.

[davidlmobley]

@MehtapIsik - I should send the e-mail since it needs to also encompass some other aspects (see Slack) so please update with what you'd want YOUR portion of it to say. We're also handling the host-guest changes at the same time, so I should do a single e-mail that covers both aspects. See the Slack channel.

[MehtapIsik]

@davidlmobley OK. I will send the email draft I prepared to you.