v0.2: scheduled release

• Fix type error in Vec\fill by Matt Glazar on 2017-08-17
• Add documentation generation to Travis test by Fred Emmott on 2017-08-17
• use use namespace by Fred Emmott on 2017-08-17
• Update dependency on definition-finder by Fred Emmott on 2017-08-17
• Revert D5622552: [hsl][PR] use use namespace by Andrew Pierce on 2017-08-15
• use use namespace by Fred Emmott on 2017-08-15
• Add FB Travis WebHook configuration by Fred Emmott on 2017-08-15
• Call builtin log with no base from Math\log by Dev Chakraborty on 2017-08-09
• Deprecate {Keyset, Vec}\keys_with_truthy_values by Kunal Mehta on 2017-08-09
• Recategorize Math\mean by Dev Chakraborty on 2017-08-08
• Use container in Math\median by Dev Chakraborty on 2017-08-07
• Use container in Math\mean by Dev Chakraborty on 2017-08-07
• Don't use 'Math' without a 'use' statement in VecSelectTest by Fred Emmott on 2017-08-06
• Use Vec\take in Vec\shuffle by Kunal Mehta on 2017-08-04
• Use keyset in Vec\unique by Kunal Mehta on 2017-08-02
• Add Travis-CI badge to README by Fred Emmott on 2017-08-02
• Unrelease parts of Random (unfinished) by Fred Emmott on 2017-08-01
• SecureRandom\bool by Dev Chakraborty on 2017-08-01
• Extract common random functions by Dev Chakraborty on 2017-08-01
• Extract RandomTestTrait from SecureRandomTest by Dev Chakraborty on 2017-08-01