Add mysqlclient to prod requirements.

* Add missing lib in dev requirements.

requirements/dev.txt

@@ -203,3 +203,6 @@ backports.os==0.1.1 \
     --hash=sha256:05b2801a021753d33e3402ac8857a3ba395eb7febbd7381fb27d880d07803061 \
     --hash=sha256:651fb7fb5d3c8c793b4306f696dff0c48a348a25c83be30455f02e818c33f86a \
     --hash=sha256:b472c4933094306ca08ec90b2a8cbb50c34f1fb2767775169a1c1650b7b74630
+entrypoints==0.3 \
+    --hash=sha256:589f874b313739ad35be6e0cd7efde2a4e9b6fea91edcc34e58ecbb8dbe56d19 \
+    --hash=sha256:c70dd71abe5a8c85e55e12c19bd91ccfeec11a6e99044204511f9ed547d48451

requirements/prod.txt

@@ -71,9 +71,6 @@ MarkupSafe==1.1.1 \
     --hash=sha256:c8716a48d94b06bb3b2524c2b77e055fb313aeb4ea620c8dd03a105574ba704f \
     --hash=sha256:cd5df75523866410809ca100dc9681e301e3c27567cf498077e8551b6d20e42f \
     --hash=sha256:e249096428b3ae81b08327a63a485ad0878de3fb939049038579ac0ef61e17e7
-MySQL-python==1.2.5 \
-    --hash=sha256:ab22d1322099098730a57fd59d610f60738f95a1cb68dacca2d1c47cb0cbe8ee \
-    --hash=sha256:811040b647e5d5686f84db415efd697e6250008b112b6909ba77ac059e140c74
 Pillow==5.3.0 \
     --hash=sha256:aa6ca3eb56704cdc0d876fc6047ffd5ee960caad52452fbee0f99908a141a0ae \
     --hash=sha256:db5499d0710823fa4fb88206050d46544e8f0e0136a9a5f5570b026584c8fd74 \
@@ -596,3 +593,7 @@ mock==2.0.0 \
     --hash=sha256:b158b6df76edd239b8208d481dc46b6afd45a846b7812ff0ce58971cf5bc8bba
 backports.ssl_match_hostname==3.7.0.1 \
     --hash=sha256:bb82e60f9fbf4c080eabd957c39f0641f0fc247d9a16e31e26d594d8f42b9fd2
+mysqlclient==1.4.2.post1 \
+    --hash=sha256:425e733b05e359a714d6007c0fc44582be66b63e5a3df0a50949274ae16f4bc6 \
+    --hash=sha256:62e4770b6a797b9416bcf70488365b7d6b9c9066878108499c559293bb464380 \
+    --hash=sha256:f257d250f2675d0ef99bd318906f3cfc05cef4a2f385ea695ff32a3f04b9f9a7