ostent 0.6.2

This is minor release featuring updated dependencies including Go 1.7 runtime and latest React.

Other notable changes:

• New --log-requests flag enables printing full access log to stdout.
  It defaults to true in dev mode, false in release binaries.
  Old behaviour was to print just the first request from a particular IP.
  So now it's to print either all the requests or none.
• The access log changed into regular (apache) common access format
  without extra fields like predefined message and duration.