Fixes ansible/ansible#523. Removed 'with:' blocks so module works with Python…

Fixes ansible/ansible#523. Removed 'with:' blocks so module works with Python 2.4 for CentOS 5 support, courtesy of mcodd/ansible@29af24b73222c97e30f5843b67e321b95fb6c979.

library/authorized_key

@@ -75,8 +75,12 @@ def get_params():
     global msg
 
     msg = "reading params"
-    with file(sys.argv[1]) as f:            #read the args file
+    argfile = sys.argv[1]
+    try:
+        f = open(argfile,"r")
         args = f.read()
+    finally:
+        f.close()
 
     msg = "writing syslog."
     syslog.openlog('ansible-%s' % os.path.basename(__file__))
@@ -118,8 +122,11 @@ def keyfile(user, create=False):
     os.chmod(sshdir, 0700)
     msg = "Touching authorized keys file."
     if not exists( keysfile):
-        with file(keysfile, "w") as f: 
-            f.write("#Authorized Keys File created by Ansible.")
+        try:
+            f = open(keysfile, "w")
+            f.write("#Authorized Keys File created by Ansible.\n")
+        finally:
+            f.close()
     os.chown(keysfile, uid, gid)
     os.chmod(keysfile, 0600)
     return keysfile
@@ -128,15 +135,21 @@ def readkeys( filename):
     global msg
     msg = "Reading authorized_keys."
     if not isfile(filename): return []
-    with file(filename) as f:
+    try:
+        f = open(filename)
         keys = [line.rstrip() for line in f.readlines()]
+    finally:
+        f.close()
     return keys
 
 def writekeys( filename, keys):
     global msg
     msg = "Writing authorized_keys."
-    with file(filename,"w") as f:
+    try:
+        f = open(filename,"w")
         f.writelines( (key + "\n" for key in keys) )
+    finally:
+        f.close()
 
 def enforce_state( params):
     """Add or remove key.
@@ -153,7 +166,7 @@ def enforce_state( params):
     state = params.get("state", "present")
 
     #== check current state
-    params["keyfile"] = keyfile(user)
+    params["keyfile"] = keyfile(user,create=True)
     keys = readkeys( params["keyfile"])
     present = key in keys