title: data.table package in R 3.5 does not install
body: <p>I am currently using R 3.5 (beta version) and I need data.table package in my project but my package does not install. Can anyone help me in the case.
  It shows me following errors when i install it.</p>
  
  <blockquote>
    <p>install.packages("data.table")
    Installing package into ‘C:/Users/hp/Documents/R/win-library/3.5’
    (as ‘lib’ is unspecified)
    --- Please select a CRAN mirror for use in this session ---
    Package which is only available in source form, and may need
      compilation of C/C++/Fortran: ‘data.table’
      These will not be installed</p>
  </blockquote>
  
  <p>I had also tried to install the package data.table_1.10.4-3.zip using CRAN repository. but it shows following errors.</p>
  
  <blockquote>
    <p>install.packages("C:/Users/hp/Downloads/data.table_1.10.4-3.zip", repos = NULL, type = "win.binary")
    Installing package into ‘C:/Users/hp/Documents/R/win-library/3.5’
    (as ‘lib’ is unspecified)
    package ‘data.table’ successfully unpacked and MD5 sums checked
    library(data.table)
    Error: package or namespace load failed for ‘data.table’:
     package ‘data.table’ was installed by an R version with different internals; it needs to be reinstalled for use with this R version</p>
  </blockquote>
  
  <p>Can anyone help me? What should I do?</p>