Update changelog and todo

CHANGELOG.md

 # Revision history for ghcup
 
+## 0.1.2 -- 2020-04-15
+
+* Fix bug when removing the set GHC version
+* Fix use of undocumented `GHCUP_INSTALL_BASE_PREFIX` variable
+* skip upgrade if ghcup is already latest version
+
 ## 0.1.1 -- 2020-04-15
 
 * fix awful fdopendir bug on mac bug by updating hpath-posix

TODO.md

@@ -2,10 +2,7 @@
 
 ## Now
 
-* ghcup migration
-* update static links
-
-* releases, update download info and bootstrap-haskell
+* move out GHCup.Version module, bc it's not library-ish
 
 ## Maybe