invert the sense of command -v

Author: nikomatsakis

ci/install.sh

@@ -2,15 +2,15 @@
 set -ex
 
 if command -v mdbook >/dev/null 2>&1; then
+    echo "mdbook already installed at $(command -v mdbook)"
+else
     echo "installing mdbook"
     cargo install mdbook --vers "0.0.28"
-else
-    echo "mdbook already installed at $(which mdbook)"
 fi
 
 if command -v ghp-import >/dev/null 2>&1; then
+    echo "ghp-import already installed at $(which ghp-import)"
+else
     echo "installing ghp-import"
     pip install ghp-import
-else 
-    echo "ghp-import already installed at $(which ghp-import)"
 fi