diff --git a/Pipfile b/Pipfile
index 3c9ee0f..b745fb8 100644
--- a/Pipfile
+++ b/Pipfile
@@ -4,6 +4,7 @@ url = "https://pypi.org/simple"
 verify_ssl = true
 
 [dev-packages]
+pytest = "*"
 
 [packages]
 pandas = "*"
diff --git a/Pipfile.lock b/Pipfile.lock
index 51a67ac..5965008 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "276cc93ee297b83cefb775fe3ab89c4f0780d81e69d4143cc95ec745efda2a4c"
+            "sha256": "71586df7dfc05695c99c4fc2a4ea3215a190b638ac3d75877180bad890d58db2"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -87,5 +87,91 @@
             "version": "==1.12.0"
         }
     },
-    "develop": {}
+    "develop": {
+        "atomicwrites": {
+            "hashes": [
+                "sha256:03472c30eb2c5d1ba9227e4c2ca66ab8287fbfbbda3888aa93dc2e28fc6811b4",
+                "sha256:75a9445bac02d8d058d5e1fe689654ba5a6556a1dfd8ce6ec55a0ed79866cfa6"
+            ],
+            "version": "==1.3.0"
+        },
+        "attrs": {
+            "hashes": [
+                "sha256:69c0dbf2ed392de1cb5ec704444b08a5ef81680a61cb899dc08127123af36a79",
+                "sha256:f0b870f674851ecbfbbbd364d6b5cbdff9dcedbc7f3f5e18a6891057f21fe399"
+            ],
+            "version": "==19.1.0"
+        },
+        "importlib-metadata": {
+            "hashes": [
+                "sha256:6dfd58dfe281e8d240937776065dd3624ad5469c835248219bd16cf2e12dbeb7",
+                "sha256:cb6ee23b46173539939964df59d3d72c3e0c1b5d54b84f1d8a7e912fe43612db"
+            ],
+            "version": "==0.18"
+        },
+        "more-itertools": {
+            "hashes": [
+                "sha256:409cd48d4db7052af495b09dec721011634af3753ae1ef92d2b32f73a745f832",
+                "sha256:92b8c4b06dac4f0611c0729b2f2ede52b2e1bac1ab48f089c7ddc12e26bb60c4"
+            ],
+            "version": "==7.2.0"
+        },
+        "packaging": {
+            "hashes": [
+                "sha256:0c98a5d0be38ed775798ece1b9727178c4469d9c3b4ada66e8e6b7849f8732af",
+                "sha256:9e1cbf8c12b1f1ce0bb5344b8d7ecf66a6f8a6e91bcb0c84593ed6d3ab5c4ab3"
+            ],
+            "version": "==19.0"
+        },
+        "pluggy": {
+            "hashes": [
+                "sha256:0825a152ac059776623854c1543d65a4ad408eb3d33ee114dff91e57ec6ae6fc",
+                "sha256:b9817417e95936bf75d85d3f8767f7df6cdde751fc40aed3bb3074cbcb77757c"
+            ],
+            "version": "==0.12.0"
+        },
+        "py": {
+            "hashes": [
+                "sha256:64f65755aee5b381cea27766a3a147c3f15b9b6b9ac88676de66ba2ae36793fa",
+                "sha256:dc639b046a6e2cff5bbe40194ad65936d6ba360b52b3c3fe1d08a82dd50b5e53"
+            ],
+            "version": "==1.8.0"
+        },
+        "pyparsing": {
+            "hashes": [
+                "sha256:43c5486cefefa536c9aab528881c992328f020eefe4f6d06332449c365218580",
+                "sha256:d6c5ffe9d0305b9b977f7a642d36b9370954d1da7ada4c62393382cbadad4265"
+            ],
+            "version": "==2.4.1.1"
+        },
+        "pytest": {
+            "hashes": [
+                "sha256:6ef6d06de77ce2961156013e9dff62f1b2688aa04d0dc244299fe7d67e09370d",
+                "sha256:a736fed91c12681a7b34617c8fcefe39ea04599ca72c608751c31d89579a3f77"
+            ],
+            "index": "pypi",
+            "version": "==5.0.1"
+        },
+        "six": {
+            "hashes": [
+                "sha256:3350809f0555b11f552448330d0b52d5f24c91a322ea4a15ef22629740f3761c",
+                "sha256:d16a0141ec1a18405cd4ce8b4613101da75da0e9a7aec5bdd4fa804d0e0eba73"
+            ],
+            "version": "==1.12.0"
+        },
+        "wcwidth": {
+            "hashes": [
+                "sha256:3df37372226d6e63e1b1e1eda15c594bca98a22d33a23832a90998faa96bc65e",
+                "sha256:f4ebe71925af7b40a864553f761ed559b43544f8f71746c2d756c7fe788ade7c"
+            ],
+            "version": "==0.1.7"
+        },
+        "zipp": {
+            "hashes": [
+                "sha256:4970c3758f4e89a7857a973b1e2a5d75bcdc47794442f2e2dd4fe8e0466e809a",
+                "sha256:8a5712cfd3bb4248015eb3b0b3c54a5f6ee3f2425963ef2a0125b8bc40aafaec"
+            ],
+            "version": "==0.5.2"
+        }
+    }
 }