I had this problem and it took me a while to resolve.
The trick is that Postgres is configured correctly. To verify that this is the case, enter the following into your terminal:
$ which psql
If you are working on a Mac and using Postgres.app, this should return something where Postgres.app can be found, for example:
$ /Applications/Postgres.app/Contents/Versions/9.3/bin/psql
" psql" , :
$ export PATH=$PATH:/Applications/Postgres.app/Contents/Versions/9.3/bin
, (.. ):
$ which psql
, "heroku pg: reset" "heroku pg: push" - ()