fix: update PTEN position based on hg38 (hms-dbmi#140)

Author: sehilyi

src/data/driver.custom.json

@@ -90,7 +90,7 @@
     {
         "gene": "PTEN",
         "chr": "chr10",
-        "pos": 89677278,
+        "pos": 87917284,
         "category": "deletion",
         "biallelic": "yes"
     }