Add support for Invert AST type (prettier#67)

Fixes prettier#58.

Author: ryanashcraft

src/printer/tokens.js

@@ -15,6 +15,7 @@ module.exports = {
   BitAnd: "&",
   BitXor: "^",
   BitOr: "|",
+  Invert: "~",
   Lt: "<",
   LtE: "<=",
   Gt: ">",

tests/python_expressions/__snapshots__/jsfmt.spec.js.snap

@@ -16,6 +16,7 @@ exports[`expressions.py 1`] = `
 90000000000000
 90000000000000.
 3j
+~3
 
 x = a + 1
 x = 1 - a
@@ -354,6 +355,7 @@ a=1;a|=2
 90000000000000
 90000000000000.
 3j
+~3
 
 x = a + 1
 x = 1 - a
@@ -772,6 +774,7 @@ exports[`expressions.py 2`] = `
 90000000000000
 90000000000000.
 3j
+~3
 
 x = a + 1
 x = 1 - a
@@ -1110,6 +1113,7 @@ a=1;a|=2
 90000000000000
 90000000000000.
 3j
+~3
 
 x = a + 1
 x = 1 - a

tests/python_expressions/expressions.py

@@ -13,6 +13,7 @@
 90000000000000
 90000000000000.
 3j
+~3
 
 x = a + 1
 x = 1 - a