Address ValueError on np.hstack (#201)

* Addressed hstack ValueError

* Updated changelog

CHANGELOG.md

@@ -34,6 +34,8 @@ release.
 -->
 
 ## [Unreleased]
+### Fixed
+- Fixed a bug in which read_ipf_str() returned a ValueError [#200](https://github.com/DOI-USGS/plio/issues/200)
 
 ## [1.5.4]()
 ### Fixed

plio/io/io_bae.py

@@ -100,7 +100,7 @@ def read_ipf_str(input_data):
                             max_rows = 1, delimiter = ',')
 
     d = [line.split() for line in open(input_data, 'r')]
-    d = np.hstack(np.array(d[3:]))
+    d = np.hstack(np.array(d[3:], dtype=object))
 
     d = d.reshape(-1, 12).astype('unicode')