Bump version to 0.1.3

CHANGELOG.md

 # Revision history for ghcup
 
+## 0.1.3 -- 2020-04-15
+
+* Fix lesser bug when skipping ghcup update
+
 ## 0.1.2 -- 2020-04-15
 
 * Fix bug when removing the set GHC version

ghcup.cabal

 cabal-version:      3.0
 name:               ghcup
-version:            0.1.2
+version:            0.1.3
 synopsis:           ghc toolchain installer as an exe/library
 description:
   A rewrite of the shell script ghcup, for providing

lib/GHCup/Version.hs

@@ -14,4 +14,4 @@ ghcupURL :: URI
 ghcupURL = [uri|https://www.haskell.org/ghcup/data/ghcup-0.0.1.json|]
 
 ghcUpVer :: PVP
-ghcUpVer = [pver|0.1.2|]
+ghcUpVer = [pver|0.1.3|]