Simplify curl on initial download
Bugfix for bash 4

Before this fix, a user that was not authy-ssh enabled trying to git push would receive the following error.

    /usr/local/bin/authy-ssh: line 428: [: git-receive-pack: unary operator expected
Prevent symlink race issues when updating the plugin.

This is done by randomizing the temp file using the command `mktemp`
Thanks to R.I.Pienaar for reporting this issue.
Merge remote-tracking branch 'orchdork10159/master' into next-release
authy-ssh: fix typo in error message "permisisons" -> "permissions"
Merge remote-tracking branch 'mobilemind/master' into next-release
Merge remote-tracking branch 'simmel/patch-1' into next-release
Fix some typos in the tests.

The tests were failing because the typo was fixed previously in the code
but the tests weren't updated.