Fix typos in docstring and error message (#261)

* Update index.md

Fix a typo.

* FIx typos in README and docs

* Fix typos in docstring and error message

Author: pitmonticone

src/convert.jl

@@ -186,7 +186,7 @@ function _pyconvert_get_rules(pytype::Py)
                 break
             end
         end
-        ok || error("Fatal inheritence error: could not merge MROs (mro=$mro, basemros=$basemros)")
+        ok || error("Fatal inheritance error: could not merge MROs (mro=$mro, basemros=$basemros)")
         # add it to the list
         push!(mro, b)
         # remove it from consideration

src/gc.jl

@@ -1,5 +1,5 @@
 """
-Garbarge collection of Python objects.
+Garbage collection of Python objects.
 
 See `disable` and `enable`.
 """