title: Install R-Package IKTrading from Github - error message
body: <p>I allow myself to post this help request as my attempts to download the R package "IKTrading" from Github repeteadly failed. I used both R V. 3.1.3. and R V.3.2.1.with identical results. </p>
  
  <p>My computer runs R on Windows 7, 64bit version. Here is the session status:</p>
  
  <pre><code>R version 3.1.3 (2015-03-09) -- "Smooth Sidewalk" Copyright (C) 2015
  The R Foundation for Statistical Computing Platform:
  x86_64-w64-mingw32/x64 (64-bit)
  </code></pre>
  
  <p>Standard recommended solutions I found on the internet did not work in my case, such as:
  - Running R as administrator (done)
  - Making sure that that Rtools is already installed (done)
  - Scrupulously respecting the order of execution of different R packages,
  including more particularly devtools and quantstrat (done all that). </p>
  
  <p>Here is the error message output for further investigation:</p>
  
  <pre><code>&gt; install_github(repo="IKTrading", username="IlyaKipnis")
  Downloading github repo IlyaKipnis/IKTrading@master
  Installing IKTrading
  Skipping 1 packages ahead of CRAN: PerformanceAnalytics
  "C:/PROGRA~1/R/R-31~1.3/bin/x64/R" --no-site-file --no-environ --no-save  \
    --no-restore CMD INSTALL "C:/Users/Cédric  \
    Spahr/AppData/Local/Temp/RtmpkP2GeU/devtools15d04c2a1d0a/IlyaKipnis-IKTrading-0b4e0e5"  \
    --library="C:/Users/Cédric Spahr/Documents/R/win-library/3.1"  \
    --install-tests 
  
  * installing *source* package 'IKTrading' ...
  Warning in file(file, ifelse(append, "a", "w")) :
    cannot open file 'C:/Users/Cidric Spahr/Documents/R/win-library/3.1/IKTrading/DESCRIPTION': No such file or directory
  Error in file(file, ifelse(append, "a", "w")) : 
    cannot open the connection
  ERROR: installing package DESCRIPTION failed for package 'IKTrading'
  * removing 'C:/Users/Cédric Spahr/Documents/R/win-library/3.1/IKTrading'
  Error: Command failed (1)
  In addition: Warning message:
  Username parameter is deprecated. Please use IlyaKipnis/IKTrading 
  </code></pre>