Default skip installed to yes

Fixes #9

README.md

@@ -17,7 +17,7 @@ makepkg will be used if no helper was found or if it's specified explicitly.
 |name           |no       |        |                                                   |Name or list of names of the package(s) to install or upgrade.|
 |upgrade        |no       |no      |yes, no                                            |Whether or not to upgrade whole system.|
 |use            |no       |auto    |auto, aurman, pacaur, trizen, pikaur, yay, makepkg |The helper to use, 'auto' uses the first known helper found and makepkg as a fallback.|
-|skip_installed |no       |no      |yes, no                                            |Skip operations if the package is present.|
+|skip_installed |no       |yes     |yes, no                                            |Skip operations if the package is present.|
 |skip_pgp_check |no       |no      |yes, no                                            |Skip verification of PGP signatures. This is useful when installing packages on a host without GnuPG (properly) configured. Only valid with makepkg.|
 
 ### Note

aur.py

@@ -40,7 +40,7 @@ options:
         description:
             - Skip operations if the package is present.
         type: bool
-        default: no
+        default: yes
 
     skip_pgp_check:
         description:
@@ -206,7 +206,7 @@ def main():
                 'choices': ['auto', 'aurman', 'pacaur', 'trizen', 'pikaur', 'yaourt', 'yay', 'makepkg'],
             },
             'skip_installed': {
-                'default': False,
+                'default': True,
                 'type': 'bool',
             },
             'skip_pgp_check': {