[DX] Prefer overmind to foreman

If available, use overmind. Fallback to foreman otherwise (windows,
preference etc).

Overmind is more stable, provides various featues as it's based on tmux,
makes it trivial to stop/restart to/attach to processes (that you
stopped with binding.irb, for example), so over all I feel like it's a
better DX.

Foreman is fine too (it's part of Omakase Rails now), so you can't
really go wrong using it either

bin/dev

@@ -1,11 +1,13 @@
 #!/usr/bin/env sh
 
-if gem list --no-installed --exact --silent foreman; then
-  echo "Installing foreman..."
-  gem install foreman
-fi
-
-# Default to port 3000 if not specified
 export PORT="${PORT:-3000}"
 
-exec foreman start -f Procfile.dev "$@"
+if command -v overmind > /dev/null 2>&1; then
+  exec overmind start -f Procfile.dev "$@"
+else
+  if gem list --no-installed --exact --silent foreman; then
+    echo "Installing foreman..."
+    gem install foreman
+  fi
+  exec foreman start -f Procfile.dev "$@"
+fi