Fix parse_url for repos with dots in name

The regex that was being used in parse_url searched until a slash (/) or dot (.) was found and then looked for an optional (.git) at the end. This caused problems with repo names like vim-scripts/ebnf.vim.git and actually caused the clone command to put the repo into a strange "git:/<user>/<repo>" directory structure.

This commit handles both urls with and without a dot in the name by selecting everything in the url after the final / as the repo name.