Remove requireNamespace("jsonlite") checks

These are no longer needed since jsonlite is in Imports now.

See #380.

R/getOptionChain.R

@@ -12,9 +12,6 @@ function(Symbols, Exp=NULL, src="yahoo", ...) {
 
 getOptionChain.yahoo <- function(Symbols, Exp, ...)
 {
-  if(!requireNamespace("jsonlite", quietly=TRUE))
-    stop("package:",dQuote("jsonlite"),"cannot be loaded.")
-
   NewToOld <- function(x, tz = NULL) {
     if(is.null(x) || length(x) < 1)
       return(NULL)

R/getOptionChain.orats.R

@@ -41,8 +41,6 @@
 }
 
 getOptionChain.orats <- function(Symbols, Exp, api.key, dte, delta) {
-  if(!requireNamespace("jsonlite", quietly=TRUE))
-    stop("package:",dQuote("jsonlite"),"cannot be loaded.")
 
   if (missing(api.key)) {
     # Check if they have ORATS_API_KEY defined

R/getSymbols.R

@@ -1099,8 +1099,6 @@ function(Symbols,env,return.class='xts',
          from=Sys.Date()-179,
          to=Sys.Date(),
          ...) {
-     if(!requireNamespace("jsonlite", quietly=TRUE))
-       stop("package:",dQuote("jsonlite"),"cannot be loaded.")
 
      importDefaults("getSymbols.oanda")
      this.env <- environment()
@@ -1230,11 +1228,6 @@ getSymbols.av <- function(Symbols, env, api.key,
   default.return.class <- return.class
   default.periodicity <- periodicity
 
-  if (!requireNamespace("jsonlite", quietly=TRUE)) {
-    stop("getSymbols.av: Package", dQuote("jsonlite"), "is required but",
-         " cannot be loaded.", call.=FALSE)
-  }
-
   #
   # For daily, weekly, and monthly data, timestamps are "yyyy-mm-dd".
   # For intraday data, timestamps are "yyyy-mm-dd HH:MM:SS".
@@ -1429,11 +1422,6 @@ getSymbols.tiingo <- function(Symbols, env, api.key,
   default.return.class <- return.class
   default.periodicity <- periodicity
 
-  if (!requireNamespace("jsonlite", quietly=TRUE)) {
-    stop("getSymbols.tiingo: Package", dQuote("jsonlite"), "is required but",
-         " cannot be loaded.", call.=FALSE)
-  }
-
   downloadOne <- function(sym, default.return.class, default.periodicity) {
 
     return.class <- getSymbolLookup()[[sym]]$return.class