Fix spelling mistakes

git ls-files | misspellings -f -
Source: https://github.com/lyda/misspell-check

Change-Id: I7d63578734ca5cc1ec865a7d024c1a013d1ada87
diff --git a/exercises/client-env.sh b/exercises/client-env.sh
index 147fdfc..6c6fe12 100755
--- a/exercises/client-env.sh
+++ b/exercises/client-env.sh
@@ -2,14 +2,14 @@
 
 # **client-env.sh**
 
-# Test OpenStack client enviroment variable handling
+# Test OpenStack client environment variable handling
 
 echo "*********************************************************************"
 echo "Begin DevStack Exercise: $0"
 echo "*********************************************************************"
 
 # This script exits on an error so that errors don't compound and you see
-# only the first error that occured.
+# only the first error that occurred.
 set -o errexit
 
 # Print the commands being run so that we can see the command that triggers