Add inline arg to VkKeyboard (#304)

Author: BrokenFG

vk_api/keyboard.py

@@ -53,14 +53,16 @@ class VkKeyboard(object):
     :type one_time: bool
     """
 
-    __slots__ = ('one_time', 'lines', 'keyboard')
+    __slots__ = ('one_time', 'lines', 'keyboard', 'inline')
 
-    def __init__(self, one_time=False):
+    def __init__(self, one_time=False, inline=False):
         self.one_time = one_time
+        self.inline = inline
         self.lines = [[]]
 
         self.keyboard = {
             'one_time': self.one_time,
+            'inline': self.inline,
             'buttons': self.lines
         }