Bump version and prepare for 0.8.1 release (#2530)

To prepare for the 0.8.1 bugfix release we need to increase the version
number and update the changelog. This commit takes care of that so we
can tag the release and trigger the builds.

CHANGELOG.rst

@@ -20,6 +20,10 @@ The format is based on `Keep a Changelog`_.
 `UNRELEASED`_
 =============
 
+
+`0.8.1`_ - 2019-05-29
+=====================
+
 Fixed
 -----
 
@@ -43,7 +47,9 @@ Fixed
 - Fix for different pulse schedules created with the same name (#2431)
 - Only create a single AquireInstruction for all qubits (#2485)
 - Stop modifying layout in stochastic swap pass (#2507)
-
+- Only call CXDirection pass on optimization_level=3 if coupling map is
+  provided (#2526)
+- Fix optimization_level=0 without a coupling map (#2509)
 
 `0.8.0`_ - 2019-05-02
 =====================
@@ -1160,7 +1166,8 @@ Fixed
 - Correct operator precedence when parsing expressions (#190).
 - Fix "math domain error" in mapping (#111, #151).
 
-.. _UNRELEASED: https://github.com/Qiskit/qiskit-terra/compare/0.8.0...HEAD
+.. _UNRELEASED: https://github.com/Qiskit/qiskit-terra/compare/0.8.1...HEAD
+.. _0.8.1: https://github.com/Qiskit/qiskit-terra/compare/0.8.0...0.8.1
 .. _0.8.0: https://github.com/Qiskit/qiskit-terra/compare/0.7.2...0.8.0
 .. _0.7.2: https://github.com/Qiskit/qiskit-terra/compare/0.7.1...0.7.2
 .. _0.7.1: https://github.com/Qiskit/qiskit-terra/compare/0.7.0...0.7.1

qiskit/VERSION.txt

@@ -1 +1 @@
-0.8.0
+0.8.1

setup.py

@@ -74,7 +74,7 @@
 
 setup(
     name="qiskit-terra",
-    version="0.8.0",
+    version="0.8.1",
     description="Software for developing quantum computing programs",
     long_description="""Terra provides the foundations for Qiskit. It allows the user to write
         quantum circuits easily, and takes care of the constraints of real hardware.""",