Added consistency with library

as.Key is renamed to as.NewKey (because NewKey is the name of the function)
client(host string, port int) is renamed to NewClient(host string, port int) - (because NewClient is the name of the function)
Merge pull request #18 from EtienneBruines/patch-1

Added consistency with library
Merge pull request #1 from aerospike/master

Merge pull request #18 from EtienneBruines/patch-1
Merged two updates of aerospike.md
Merge branch 'patch-1'