use read_table2 to read whitespace-delimited text; fixes #1661

read_table requires columns to be aligned, but many real-world
whitespace-delimited data files do not have aligned columns.
read_table2, new in readr 1.1.0, does not require columns to be aligned
but otherwise behaves similarly to read_table.

src/cpp/session/modules/SessionDataImportV2.R

@@ -406,8 +406,8 @@
          }
          else if (identical(dataImportOptions$delimiter, " "))
          {
-            functionName <- "read_table"
-            functionReference <- readr::read_table
+            functionName <- "read_table2"
+            functionReference <- readr::read_table2
          }
          else
          {

src/gwt/src/org/rstudio/studio/client/common/dependencies/DependencyManager.java

@@ -384,7 +384,7 @@ public void execute(Boolean succeeded)
    private ArrayList<Dependency> dataImportCsvDependencies()
    {
       ArrayList<Dependency> deps = new ArrayList<Dependency>();
-      deps.add(Dependency.cranPackage("readr", "0.2.2"));
+      deps.add(Dependency.cranPackage("readr", "1.1.0"));
       deps.add(Dependency.cranPackage("Rcpp", "0.11.5"));
       return deps;
    }