Bump version to 0.13.1

Signed-off-by: Stefan Widgren <stefan.widgren@gmail.com>

Author: stewid

DESCRIPTION

@@ -4,7 +4,7 @@ Description: Interface to the 'libgit2' library, which is a pure C
     implementation of the 'Git' core methods. Provides access to 'Git'
     repositories to extract data and running some basic 'Git'
     commands.
-Version: 0.13.0.9000
+Version: 0.13.1
 License: GPL-2
 Copyright: See COPYRIGHTS file.
 URL: https://github.com/ropensci/git2r

NEWS

@@ -1,4 +1,4 @@
-git2r 0.13.0
+git2r 0.13.1
 ------------
 
 BUG FIXES
@@ -15,10 +15,7 @@ BUG FIXES
     warning (arithmetic on a pointer to void is a GNU extension
     [-Wpointer-arith]) on r-devel-osx-x86_64-clang.
 
-CHANGES
-
-* Set PKG_CFLAGS in the build configuration on OS X to
-  '-Wno-deprecated-declarations'
+  - Several fixes to the build configuration on non-Windows platforms.
 
 git2r 0.12.1
 ------------