Requirement.txt has minor typo (#18)

soechun · localminimum · commit a2401dd755a0 · 2018-04-24T16:06:20.000+12:00
it should be spacy ==2.0.0
diff --git a/requirements.txt b/requirements.txt
@@ -1,4 +1,4 @@
 nltk==3.2.4
 numpy==1.13.1
 tqdm==4.15.0
-spacy=2.0.0
+spacy==2.0.0
