formatted conda completion and used helper function

completion/available/conda.completion.bash

@@ -1,4 +1,12 @@
 #!/usr/bin/env bash
-which register-python-argcomplete > /dev/null \
-  && eval "$(register-python-argcomplete conda)" \
-  || echo "Please install argcomplete to use conda completion"
+
+if _command_exists conda
+then
+    if _command_exists register-python-argcomplete
+    then
+        eval "$(register-python-argcomplete conda)"
+    else
+        _log_warning "Argcomplete not found. Please run 'conda install argcomplete'"
+        return 1
+    fi
+fi