Add iso-639 library to validate languages

Pipfile

@@ -12,6 +12,7 @@ flake8 = "*"
 pandas = "*"
 python-stdnum = "*"
 xlrd = "*"
+iso-639 = "*"
 
 [requires]
 python_version = "3.7"

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "5fa81e553c4f7f25d8e05b1ffec5d65f6661c2351274bca97fb50041bd84f9c5"
+            "sha256": "d5c625fc9bd915e3199fc4f617c157ee002795fa44d9fa6f0a298749acc134e6"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -16,6 +16,13 @@
         ]
     },
     "default": {
+        "iso-639": {
+            "hashes": [
+                "sha256:dc9cd4b880b898d774c47fe9775167404af8a85dd889d58f9008035109acce49"
+            ],
+            "index": "pypi",
+            "version": "==0.4.5"
+        },
         "numpy": {
             "hashes": [
                 "sha256:03e311b0a4c9f5755da7d52161280c6a78406c7be5c5cc7facfbcebb641efb7e",
@@ -141,10 +148,10 @@
         },
         "importlib-metadata": {
             "hashes": [
-                "sha256:6dfd58dfe281e8d240937776065dd3624ad5469c835248219bd16cf2e12dbeb7",
-                "sha256:cb6ee23b46173539939964df59d3d72c3e0c1b5d54b84f1d8a7e912fe43612db"
+                "sha256:23d3d873e008a513952355379d93cbcab874c58f4f034ff657c7a87422fa64e8",
+                "sha256:80d2de76188eabfbfcf27e6a37342c2827801e59c4cc14b0371c56fed43820e3"
             ],
-            "version": "==0.18"
+            "version": "==0.19"
         },
         "ipython": {
             "hashes": [