Make SMILES parsing of [C] give triplet state (and test it).

Apparently the ground state is a triplet. Closes #946
(Although whether we react it correctly as a triplet, I cannot guarantee...)

Author: rwest

rmgpy/molecule/parser.py

@@ -54,6 +54,12 @@
             multiplicity 1
             1 Ar u0 p4
             """,
+    '[C]':  # We'd return the quintuplet without this
+            """
+            multiplicity 3
+            1 C u2 p1 c0
+            """,
+
 }     
 
 def __fromSMILES(mol, smilesstr, backend):

rmgpy/molecule/parserTest.py

@@ -278,6 +278,15 @@ def test_fromSMILES(self):
         self.compare(adjlist, smiles)
 
 
+        # Test atomic C, which is triplet in ground state
+        adjlist = '''
+        multiplicity 3
+        1 C u2 p1 c0
+        '''
+        smiles = '[C]'
+        self.compare(adjlist, smiles)
+
+
         # Test O2
         adjlist = '''
         multiplicity 3