corrr 0.3.2

• Improves support for tbl_sql() objects

• Switches correlation calculation for tbl_spark() tables to sparklyr::ml_corr()

• Adds package level doc (@jsta, #66)

• Fixes typo on error message (@jsta)

• Removes Database vignette. Plan to re-add later on (#76)

• Minor updates to Using corrr vignette