update Springer SocPsych Author date:
- uses regular 8/6 et al. doesn't follow APA 6th (key style points)
- uses different URL/accessed format from APA (key style points)
- uses "and", not & for in text citations (key style points suggest that, saying in text citations follow standard Harvard, sampling of journals confirms)
- et al for 3-1 from the first citation, confirmed by published journals.
Merge branch 'master' of github.com:citation-style-language/styles

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